Methods, compositions, and compounds for allosteric modulation of the GABA receptor by members of the androstane and pregnane series

ABSTRACT

Methods, compositions, and compounds for modulating the GABAA receptor-chloride ionophore complex to alleviate stress, anxiety, seizures, mood disorders, PMS and PND and to induce anesthesia.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application No. 08/887,229,filed Jul. 2, 1997, now U.S. Pat. No. 5,939,545 which is a continuationof U.S. application No. 08/389,829, filed Feb. 14, 1995, now abandoned,which is a continuation-in-part of U.S. application No. 08/346,927,filed Nov. 23, 1994, now abandoned, which is a continuation-in-part ofU.S. application No. 08/196,919, filed Feb. 14, 1994, now abandoned, thecontents of each of which are fully incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention is directed to methods, compositions, andcompounds for modulating animal (and human) brain excitability via thegamma-aminobutyric acid A (GABA_(A)) receptor-chloride ionophore complex(GRC). Specifically, the present invention is directed to methods,compositions, and compounds for modulating brain excitability throughbinding to the neurosteroid receptor site on the GRC.

Brain excitability is defined as the level of arousal of an animal, acontinuum that ranges from coma to convulsions, and is regulated byvarious neurotransmitters. In general, neurotransmitters are responsiblefor regulating the conductance of ions across neuronal membranes. Atrest, the neuronal membrane possesses a potential (or membrane voltage)of approximately -80 mV, the cell interior being negative with respectto the cell exterior. The potential (voltage) is the result of ion (K⁺,Na⁺, Cl⁻, organic anions) balance across the neuronal semipermeablemembrane. Neurotransmitters are stored in presynaptic vesicles and arereleased under the influence of neuronal action potentials. Whenreleased into the synaptic cleft, an excitatory chemical transmittersuch as acetylcholine will cause membrane depolarization (change ofpotential from -80 mV to -50 mV). This effect is mediated bypostsynaptic nicotinic receptors which are stimulated by acetylcholineto increase membrane permeability to Na⁺ ions. The reduced membranepotential stimulates neuronal excitability in the form of a postsynapticaction potential.

In the case of the GRC, the effect on brain excitability is mediated byGABA, a neurotransmitter. GABA has a profound influence on overall brainexcitability because up to 40% of the neurons in the brain utilize GABAas a neurotransmitter. GABA regulates the excitability of individualneurons by regulating the conductance of chloride ions across theneuronal membrane. GABA interacts with its recognition site on the GRCto facilitate the flow of chloride ions down an electrochemical gradientof the GRC into the cell. An intracellular increase in the levels ofthis anion causes hyperpolarization of the transmembrane potential,rendering the neuron less susceptible to excitatory inputs (i.e. reducedneuron excitability). In other words, the higher the chloride ionconcentration in the neuron, the lower the brain excitability (the levelof arousal).

It is well-documented that the GRC is responsible for the mediation ofanxiety, seizure activity, and sedation. Thus, GABA and drugs that actlike GABA or facilitate the effects of GABA (e.g., the therapeuticallyuseful barbiturates and benzodiazepines (BZs) such as Valium) producetheir therapeutically useful effects by interacting with specificregulatory sites on the GRC.

It has also been observed that a series of steroid metabolites interactwith the GRC to alter brain excitability (Majewska, M. D. et al.,"Steroid hormone metabolites are barbiturate-like modulators of the GABAreceptor," Science 232:1004-1007 (1986); Harrison, N. L. et al.,Structure-activity relationships for steroid interaction with thegamma-aminobutyric acid-A receptor complex," J. Pharmacol. Exp. Ther.241:346-353 (1987)). Prior to the present invention, the therapeuticusefulness of these steroid metabolites was not recognized by workers inthe field due to an incomplete understanding of the potency and site ofaction. Applicants' invention relates in part to a pharmaceuticalapplication of the knowledge gained from a more developed understandingof the potency and site of action of certain steroid compounds.

The ovarian hormone progesterone and its metabolites have beendemonstrated to have profound effects on brain excitability (Backstrom,T. et al., "Ovarian steroid hormones: effects on mood, behavior andbrain excitability," Acta Obstet. Gynecol. Scand. Suppl. 130:19-24(1985); Pfaff, D. W. and McEwen, B. S., "Actions of estrogens andprogestins on nerve cells," Science 219:808-814 (1983); Gyermek et al.,"Structure activity relationship of some steroidal hypnotic agents," J.Med. Chem. 11:117 (1968); Lambert, J. et al., "Actions of synthetic andendogenous steroids on the GABA_(A) receptor," Trends Pharmacol.8:224-227 (1987)). The levels of progesterone and its metabolites varywith the phases of the menstrual cycle. It has been well documented thatprogesterone and its metabolites decrease prior to the onset of menses.The monthly recurrence of certain physical symptoms prior to the onsetof menses has also been well documented. These symptoms, which havebecome associated with premenstrual syndrome (PMS) include stress,anxiety, and migraine headaches (Dalton, K., Premenstrual Syndrome andProgesterone Therapy, 2nd edition, Chicago: Chicago yearbook, 1984).Patients with PMS have a monthly recurrence of symptoms that are presentin premenses and absent in postmenses.

In a similar fashion, a reduction in progesterone has also beentemporally correlated with an increase in seizure frequency in femaleepileptics (i.e., catamenial epilepsy; Laidlaw, J., "Catamenialepilepsy," Lancet, 1235-1237 (1956)). A more direct correlation has beenobserved with a reduction in progesterone metabolites (Rosciszewska etal., "Ovarian hormones, anticonvulsant drugs and seizures during themenstrual cycle in women with epilepsy," J. Neurol. Neurosurg. Psych.49:47-51 (1986)). In addition, for patients with primary generalizedpetit mal epilepsy, the temporal incidence of seizures has beencorrelated with the incidence of the symptoms of premenstrual syndrome(Backstrom, T. et al., "Endocrinological aspects of cyclical moodchanges during the menstrual cycle or the premenstrual syndrome," J.Psychosom. Obstet. Gynaecol. 2:8-20 (1983)). The steroiddeoxycorticosterone has been found to be effective in treating patientswith epileptic spells correlated with their menstrual cycles (Aird, R.B. and Gordan, G., "Anticonvulsive properties of deoxycorticosterone,"J. Amer. Med. Soc. 145:715-719 (1951)).

A syndrome also related to low progesterone levels is postnataldepression (PND). Immediately after birth, progesterone levels decreasedramatically leading to the onset of PND. The symptoms of PND range frommild depression to psychosis requiring hospitalization; PND isassociated with severe anxiety and irritability. PND-associateddepression is not amenable to treatment by classic antidepressants andwomen experiencing PND show an increased incidence of PMS (Dalton, K.,1984).

Collectively, these observations imply a crucial role for progesteroneand deoxycorticosterone and more specifically their metabolites in thehomeostatic regulation of brain excitability, which is manifested as anincrease in seizure activity or symptoms associated with catamenialepilepsy, PMS, and PND. The correlation between reduced levels ofprogesterone and the symptoms associated with PMS, PND, and catamenialepilepsy (Backstrom et al., 1983; Dalton, K., 1984) has prompted the useof progesterone in their treatment (Mattson et al., "Medroxyprogesteronetherapy of catamenial epilepsy, " in Advances in epileptology: XVthEpilepsy International Symposium, Raven Press, New York, 279-282, 1984,and Dalton, K., 1984). However, progesterone is not consistentlyeffective in the treatment of the aforementioned syndromes. For example,no dose-response relationship exists for progesterone in the treatmentof PMS (Maddocks, et al., "A double-blind placebo-controlled trial ofprogesterone vaginal suppositories in the treatment of premenstrualsyndrome," Obstet. Gynecol. 154:573-581 (1986); Dennerstein, et al.,British Medical Journal, 290:16-17 (1986)).

The publications and references referred to above and hereafter in thisspecification are incorporated herein by reference.

SUMMARY OF THE INVENTION

The present invention is directed to methods, compositions, andcompounds for modulating brain excitability. More particularly, theinvention relates to the use of 3α-hydroxylated steroid derivatives,acting at a newly identified site on the GR complex, to modulate brainexcitability in a manner that will alleviate stress, anxiety, insomnia,mood disorders (such as depression) that are amenable to GR-activeagents, and seizure activity. Compositions and compounds effective forsuch treatment are within the scope of the invention.

The compounds used in and forming part of the invention are modulatorsof the excitability of the central nervous system as mediated by theirability to regulate chloride ion channels associated with the GABA_(A)receptor complex. Applicants' experiments have established that thecompounds used in and of the invention have anticonvulsant andanxiolytic activity similar to the actions of known anxiolytic agentssuch as the BZs, but act at a distinct site on the GR complex.

The relationship of endogenous metabolites of progesterone to processesassociated with reproduction (estrus cycle and pregnancy) is wellestablished (Marker, R. E., Kamm, O., and McGrew, R. V., "Isolation ofepi-pregnanol-3-one-20 from human pregnancy urine," J. Am. Chem. Soc.59:616-618 (1937)). Prior to the present invention, however, it was notrecognized how to treat disorders by modulating brain excitabilitythrough the use of progesterone metabolites amd their derivatives.Therefore, this invention is directed to methods, compositions, andcompounds to treat disorders by modulating brain excitability using thecompounds of this invention. Representative disorders treated in thepresent invention are epilepsy, anxiety, pre-menstrual syndrome (PMS),post-natal depression (PND), mood disorders (such as depression) thatare amenable to GR-active agents, and insomnia. The compounds of theinvention can also be used to induce anesthesia.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood and its advantagesappreciated by those skilled in the art by referring to the accompanyingdrawings wherein:

FIGS. 1A and 1B are plots of the percent binding of [³⁵ S]t-butylbicyclophosphorothionate ([³⁵ S] TBPS) to the cell membranes ofrat brain vs. log concentration of the alphaxalone (also calledalfaxalone) and GABA in various concentrations of (+)bicuculline.

FIG. 2 shows time courses for the dissociation of 2 nM [³⁵ S] TBPS fromrat cortical P₂ homogenates initiated by the addition of 2 μM TBPS (▪),1 μM 3α5αP (□), 100 μM Na pentobarbital (), and 1 μM 3α5αP+100 μM Napentobarbital (∘).

FIG. 3 is a plot showing the effect of a single dosage of pentobarbitalon 3α-OH-5α-pregnan-20-one (3α-5α-P) modulation of [³ H]-flunitrazepambinding in rat hippocampal homogenates.

FIG. 4 is a plot of the effect of 3α-hydroxy-5α-pregnan-20-one,3α,21-dihydroxy-5α-pregnan-20-one (5α-THDOC) and R5020 (promegesterone)on inhibiting [³⁵ S] TBPS binding in rat cerebral cortex homogenate.

FIG. 5 is a plot of the correlation between TBPS binding andelectrophysiological activity of 15 different 3α-hydroxylated steroids.

FIG. 6 is a plot of the effect of 3α-OH-5α-pregnan-20-one,5α-pregnan-3α,20α-diol and 5β-pregnan-3α,20β-diol on inhibiting [³⁵ S]TBPS binding in rat cortex homogenate.

FIG. 7 is a plot showing the effect of 3α-OH-5α-pregnan-20-one,5α-pregnan-3α,20α-diol, and 5β-pregnan-3α,20β-diol on the GABA-evokedcurrent in Xenopus oocytes injected with human recombinant GABA receptorsubunit α1β1γ2L.

FIG. 8 is a line graph of the number of transitions from light to darkoccurring within ten minutes of injection of 3α-OH-5α-pregnan-20-one and3α-OH-5β-pregnan-20-one.

FIGS. 9A and 9B are two line graphs of the percentage of (A) entriesinto and (B) the time on the open-arms during a five-minute test periodof 3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one in the elevatedplus-maze test.

FIG. 10 is a line graph of the change in punished rats responding frombaseline for 3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one in theGeller Seifter test.

FIG. 11 is a plot of the time course of anti-metrazol activity ofseveral prodrugs of 3α-OH-5α-pregnan-20-one.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The compounds of and used in the invention are derivatives of various3α-hydroxylated-pregnanes and 3α-hydroxylated-androstanes, and ester,ether, sulfonate, sulfate, phosphonate, phosphate, oxime, thiosulfate,heterocyclic and heteroaryl derivatives thereof, and derivativesreferred to as prodrugs. The expression "prodrug" denotes a derivativeof a known direct acting drug, which derivative has enhanced deliverycharacteristics and therapeutic value as compared to the drug, and istransformed into the active drug by an enzymatic or chemical process;see Notari, R. E., "Theory and Practice of Prodrug Kinetics," Methods inEnzymology, 112:309-323 (1985); Bodor, N., "Novel Approaches in ProdrugDesign," Drugs of the Future, 6(3):165-182 (1981); and Bundgaard, H.,"Design of Prodrugs: Bioreversible-Derivatives for Various FunctionalGroups and Chemical Entities," in Design of Prodrugs (H. Bundgaard,ed.), Elsevier, New York (1985). It should be noted that some of thesynthetic derivatives forming part of the present invention may not betrue prodrugs because, in addition to the above characteristics, theyalso possess intrinsic activity. However, for purposes of thisapplication they will be referred to as prodrugs.

Our studies (Gee, K. W. et al., "GABA-dependent modulation of the Clionophore by steroids in rat brain," European Journal of Pharmacology,136:419-423, 1987) have demonstrated that the 3α-hydroxylated steroidsused in the invention are orders of magnitude more potent than othershave reported (Majewska, M. D. et al. (1986) and Harrison, N. L. et al.(1987)) as modulators of the GR complex. Majewska et al. and Harrison etal. teach that the 3α-hydroxylated-5-reduced steroids are only capableof much lower levels of effectiveness. Our in vitro and in vivoexperimental data demonstrate that the high potency of these steroidsallows them to be therapeutically useful in the modulation of brainexcitability via the GR complex. The most potent steroids useful in thepresent invention include derivatives of major metabolites ofprogesterone and deoxycorticosterone. These steroids can be specificallyused to modulate brain excitability in stress, anxiety, insomnia, mooddisorders (such as depression) that are amenable to GR-active agents,and seizure disorders in a therapeutically beneficial manner.Furthermore, we have demonstrated that these steroids interact at aunique site on the GR complex which is distinct from other known sitesof interaction (i.e., barbiturate, BZ, and GABA) where therapeuticallybeneficial effects on stress, anxiety, sleep, mood disorders and seizuredisorders have been previously elicited (Gee, K. W. and Yamamura, H. I.,"Benzodiazepines and Barbiturates: Drugs for the Treatment of Anxiety,Insomnia and Seizure Disorders," in In Central Nervous System Disorders,pages 123-147, D. C. Horvell, ed., 1985; Lloyd, K. G. and Morselli, P.L., "Psychopharmacology of GABAergic Drugs," in Psychopharmacology: TheThird Generation of Progress, pages 183-195, H. Y. Meltzer, ed., RavenPress, N.Y., 1987). These compounds are desirable for their duration,potency and oral activity (along with other forms of administration).

The steroid derivatives of this invention are those having one of thefollowing structural formula (I): ##STR1## wherein R, R₁, R₂, R₃, R₄,R₅, R₆, R₇, R₈, R₉ and R₁₀ are further defined herein and the dottedlines are single or double bonds. The structure having Formula Iincludes androstanes, pregnanes (R₄ =methyl), 19-nor-androstanes, andnorpregnanes (R₄ ═H).

The present invention also includes pharmaceutically acceptable estersand salts of the compounds of Formula I, including acid addition salts.It is believed that the 3α-hydroxyl may also be masked as apharmaceutically acceptable ester due to the fact that the ester will becleaved off as the prodrug is converted to drug form. These are referredto herein as cleavable esters.

Definitions

In accordance with the present invention and as used herein, thefollowing terms are defined with the following meaning, unlessexplicitly stated otherwise.

The term "alkyl" refers to saturated aliphatic groups including straightchain, branched chain, and cyclic groups, all of which may be optionallysubstituted. Suitable alkyl groups include methyl, ethyl, and the like,and may be optionally substituted.

The term "alkenyl" refers to unsaturated groups which contain at leastone carbon-carbon double bond and includes straight chain, branchedchain, and cyclic groups, all of which may be optionally substituted.

The term "alkynyl" refers to unsaturated hydrocarbon groups whichcontain at least one carbon-carbon triple bond and includes straightchain and branched chain groups which may be optionally substituted.Suitable alkynyl groups include propynyl, pentynyl, and the like whichmay be optionally substituted with cyano, acetoxy, halo, hydroxy orketo. Preferred alkynyl groups have five to eighteen carbon atoms. Morepreferred alkynyl groups have five to twelve carbon atoms. Mostpreferred alkynyl groups have five to seven carbon atoms.

The term "alkoxy" refers to the ether --OR wherein R is alkyl.

The term "aryloxy" refers to the ether --OR wherein R is aryl.

The term "aryl" refers to aromatic groups which have at least one ringhaving a conjugated pi electron system and includes carbocyclic aryl andbiaryl, both of which may be optionally substituted.

The term "carbocyclic aryl" refers to groups wherein the ring atoms onthe aromatic ring are carbon atoms. Carbocyclic aryl groups includephenyl and naphthyl groups optionally substituted. Substituted phenylhas preferably one to three, four or five substituents, such beingadvantageously, lower alkyl, amino, amido, cyano, carboxylate ester,hydroxy, lower alkoxy, halogen, lower acyl, and nitro.

The term "aralkyl" refers to an alkyl group substituted with an arylgroup. Suitable aralkyl groups include benzyl, and the like, and may beoptionally substituted.

The term "alkanoyloxy" refers to --O--C(O)R, wherein R is alkyl,alkenyl, alkynyl, aryl or aralkyl.

The term "carbalkoxyl" refers to --C(O)OR, wherein R is alkyl, alkenyl,alkynyl, aryl or aralkyl.

The term "carboxamido" refers to --C(O)NRR₁, wherein R and R₁ areindependently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl oraralkyl.

The term "dialkylamino" refers to --NRR" where R and R" areindependently lower alkyl groups or together form the rest of amorpholino group. Suitable dialkylamino groups include dimethyl amino,diethylamino, and morpholino.

The term "acyl" refers to the alkanoyl group --C(O)R where R is alkyl,alkenyl, alkynyl, aryl, or aralkyl.

The term "amino" refers to NRR', wherein R and R' are independentlyhydrogen, lower alkyl or are joined together to give a 5 or 6-memberedring, e.g. pyrrolidine or piperidine rings.

The term "optionally substituted" or "substituted" refers to groupssubstituted by one to three, four or five substituents, independentlyselected from lower alkyl (acylic and cyclic), aryl (carboaryl andheteroaryl), alkenyl, alkynyl, alkoxy, halo, haloalkyl (includingtrihaloalkyl, e.g. trifluoromethyl), amino, mercapto, alkylthio,alkylsulfinyl, alkylsulfonyl, nitro, alkanoyl, alkanoyloxy,alkanoyloxyalkanoyl, alkoxycarboxy, carbalkoxy (--COOR, wherein R islower alkyl), carboxamido (--CONRR', wherein R and R' are independentlylower alkyl), formyl, carboxyl, hydroxy, cyano, azido, keto and cyclicketals thereof, alkanoylamido, heteroaryloxy, heterocarbocyclicoxy, andhemisuccinate ester salts.

The term "lower" is referred to herein in connection with organicradicals or compounds defines such as one up to and including ten,preferably up to and including six, and advantageously one to fourcarbon atoms. Such groups may be straight chain, branched chain, orcyclic.

The term "heterocyclic" refers to carbon containing radicals havingfour, five, six, or seven membered rings and one, two or three O, N or Sheteroatoms, e.g., thiazolidine, tetrahydrofuran, 1,4-dioxane,pyrrolidine, piperidine, quinuclidine, dithiane, tetrahydropyran,ε-caprolactone, ε-caprolactam, ω-thiocaprolactam, and morpholine.

The term "heteroaryl" refers to carbon containing 5-14 membered cyclicunsaturated radicals containing one, two, three or four O, N or S atomsand having 6, 10 or 14π electrons delocalized in one or more rings,e.g., pyridine, oxazole, indole, purine, pyrimidine, imidazole,benzimidazole, indazole, 2H-1,2,4-triazole, 1,2,3-triazole,2H-1,2,3,4-tetrazole, 1H-1,2,3,4-tetrazole, benzotriazole,1,2,3-triazolo[4,5-b]pyridine, thiazole, isoxazole, pyrazole, quinoline,cytosine, thymine, uracil, adenine, guanine, pyrazine, picolinic acid,picoline, furoic acid, furfural, furyl alcohol, carbazole,9H-pyrido[3,4-b]indole, isoquinoline, pyrrole, thiophene, furan,9(10H)-acridone, phenoxazine, and phenothiazine, each of which may beoptionally substituted as discussed above.

The term "dioic acids" refers to C₁₋₅ alkylene groups substituted withtwo carboxy groups, for example, malonic acid, succinic acid, glutaricacid, adipic acid, pimelic acid, and suberic acid. Hemi-ester salts ofthe dioic acids include the sodium, lithium, potassium, magnesium andcalcium salts thereof.

The term "β-acetyl-thiosulfate salt" refers is intended to include thesodium, lithium, potassium, magnesium and calcium salts thereof.

The term "pharmaceutically acceptable esters or salts" refers to estersor salts of Formula I derived from the combination of a compound of thisinvention and an organic or inorganic acid or base.

According to the present invention, ketals include diethers of loweralkanols, e.g. dimethyl and diethyl ketals, as well as cyclic ketalswhich include diethers of C₂₋₃ alkanediols, e.g. ethylene ketals andpropylene ketals.

Examples of substituents which can be used in the compounds of Formula Iare:

R is hydrogen, halogen, optionally substituted 1-alkynyl, lower alkoxy,alkyl, dialkylamino, or substituted alkyl;

R₁ is a substituted aralkynyl, arylalkyl, arylalkenyl, aryl, optionallysubstituted aralkylalkynyl, alkanoyloxyalkynyl, optionally substitutedheteroaryloxyalkynyl, oxoalkynyl or a ketal thereof, cyanoalkynyl,optionally substituted heteroarylalkynyl, hydroxyalkynyl, alkoxyalkynyl,aminoalkynyl, acylaminoalkynyl, mercaptoalkynyl, hydroxyalkynyl dioicacid hemi-ester or a salt thereof, or alkynyloxyalkynyl;

R₂ is hydrogen, hydroxy, alkoxy, alkanoyloxy, carbalkoxyl, a keto groupor amino group;

R₃ is an acetyl group, a ketal of an acetyl group; an alkoxyacetylgroup, an alkylthioacetyl group, an alkylsulfinylacetyl group, analkylsulfonylacetyl group, an aminoacetyl group, a trifluoroacetylgroup; a hydroxyacetyl group; an alkoxyalkylacetyl group, e.g. amethoxymethylacetyl group or an ethoxymethyl-2'-methylene acetyl group;a hydroxyalkyl group, e.g. a hydroxymethyl group, a 1'-hydroxyethylgroup, a 1'-hydroxypropyl group, or a 2'-hydroxy-2'-propyl group; ahydroxyacetyl dioic acid hemi-ester salt, e.g. a succinyloxyacetylgroup; an alkanoyloxyacetyl group, e.g. an acetoxyacetyl group; or asulfoxyacetyl group; an alkylacetyl group, e.g. a methylacetyl group; ahaloacetyl group; an ethynyl group; an optionally substitutedheteroarylacetyl group; an optionally substituted heteroaralkylacetylgroup which is also optionally substituted on the alkylene with ahydroxy, alkoxy, alkanoyloxy or carbalkoxyl group; an optionallysubstituted heterocyclic-acetyl group; an acetyl thiosulfate salt; acyano group; a alkylmethylene group (together with R₇); or analkoxymethylene group (together with R₇);

R₄ is hydrogen or methyl,

R₅ is hydrogen;

R₆ is hydrogen, alkanoyl, aminocarbonyl, or alkoxycarbonyl;

R₇ is hydrogen, halogen, hydroxy, alkoxy, alkanoyloxy, carbalkoxyl, amethylene group (together with R₃), or an alkoxymethylene group(together with R₃);

R₈ is hydrogen or halogen;

R₉ is hydrogen, halogen, alkyl, alkoxy, arylalkoxy or amino; and

R₁₀ is hydrogen, halogen, alkyl, haloalkyl, hydroxy, alkoxy,alkanoyloxy, carbalkoxyl, cyano, thiocyano or mercapto; provided thatwhen R₃ is an optionally substituted heteroarylacetyl group oracetylthiosulfate salts or when R is an optionally substituted 1-alkynylgroup, then R₁ may further be hydrogen, alkyl, alkenyl, aryl, aralkyl,alkynyl, optionally substituted aralkynyl, alkoxyalkyl, aminoalkyl,cyano, cyanoalkyl, thiocyanoalkyl, or azidoalkyl.

A preferred group of compounds of Formula I are compounds where R ishydrogen or lower alkoxy. More preferred are compounds where R, R₅, R₆,R₇, R₈, R₉ and R₁₀ are hydrogen.

Another group of preferred compounds are compounds of Formula I where R₁is substituted aralkynyl, e.g. R₁ is 4-substituted phenylalkynyl such as4-acetylphenylethynyl, 4-methoxyphenylethynyl,4-N,N-dimethylaminophenylethynyl, 4-cyanophenylethynyl,4-carboxyphenylethynyl ethyl ester, 4-N,N-dialkylamidophenylethynyl, orwhere R₁ is oxoalkynyl, hydroxyalkynyl, acetoxyalkynyl, cyanoalkynyl, oralkoxyalkynyl.

An additional group of preferred compounds are wherein R₃ is acetyl,heteroarylacetyl, heterocyclic-acetyl, hydroxyalkyl, hydroxyacetyl, andtheir esters with physiologically acceptable acids. More preferably, R₃is acetyl, β-succinyloxyacetyl, alkoxyacetyl, acetylthiosulfate salts,pyrazolylacetyl, or imidazolylacetyl.

An additional group of preferred compounds are wherein:

R is hydrogen, fluoro, chloro or lower alkoxy;

R₁ is substituted arylethynyl;

R₂ is hydrogen, a keto group or a dimethylamino group;

R₃ is a β-acetyl group, a dimethyl ketal of a β-acetyl group, atrifluoroacetyl group, a β-(hydroxyacetyl) group, aβ-methoxymethylacetyl group, a β-(ethoxy)methyl-2'-methylene acetylgroup, a β-(1'-hydroxyethyl) group, a β-(1'-hydroxypropyl) group, aβ-(2'-hydroxy-2'propyl) group, a β-succinyloxyacetyl group, aβ-hydroxyacetyl sodium succinate group, a β-acetoxyacetyl group, aβ-sulfoxyacetyl group, a β-methylacetyl group, a β-chloroacetyl group,or a β-ethynyl group;

R₄ is hydrogen or methyl;

R₅, R₆, R₇, R₈, R₉ and R₁₀ are hydrogen;

the dotted lines all represent single bonds; and

R₇ is hydrogen or, when R₃ is β-hydroxyacetyl, R₇ is hydrogen orhydroxy.

Further preferred compounds are compounds of Formula I which are estersof hydroxyl groups at positions 3, 20 and/or 21. Preferred esters arethose obtained from their corresponding acids and dioic acids: acetic,propionic, maleic, fumaric, ascorbic, pimelic, succinic, glutaric,bismethylene-salicylic, methanesulfonic, ethane-di-sulfonic, oxalic,tartaric, salicylic, citric, gluconic, itaconic, glycolic,p-aminobenzoic, aspartic, glutamic, gamma-amino-butyric,α-(2-hydroxyethylamino)propionic, glycine and other α-amino acids,phosphoric, sulfuric, glucuronic, and 1-methyl-1,4-dihydronicotinic.

Preferred are the following compounds:3α-hydroxy-3β-phenylethynyl-5β-pregnan-20-one,3α-hydroxy-3β-phenylethynyl-5α-pregnan-20-one,3α-hydroxy-3β-(3',4'-dimethoxyphenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(4'-methylphenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(2'-methoxyphenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(4'-carboxyphenyl)ethynyl-5β-pregnan-20-one ethyl ester,3α-hydroxy-3β-(4'-acetoxyacetylpbenyl)ethynyl-5β-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-dimethylaminophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3.alpha.-hydroxy-3β-(4'-nitrophenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(4'-methoxyphenyl)ethynyl-5β-pregnan-20-one,3β-(4'-trifluoromethylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-chlorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-cyanophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'(R/S)-hydroxypentynyl)-3α-hydroxy-5β-pregnan-20-one,3α-hydroxy-3β-phenyl-5β-pregnan-20-one,3α-hydroxy-3β-benzyl-5β-pregnan-20-one,3α-hydroxy-3β-(2'-phenylethyl)-5β-pregnan-20-one,3α-hydroxy-3β-[2-(3',4'-dimethoxyphenyl)ethyl]-5β-pregnan-20-one,3α-hydroxy-3β-[6'-oxo-1'-heptynyl]-5β-pregnan-20-one,3α-hydroxy-3β-(7'-oxo-1'-octynyl)-5β-pregnan-20-one,3α-hydroxy-3β-(4'-oxo-1'-pentynyl)-5β-pregnan-20-one,3β-[5'-(R/S)-hydroxyhexynyl]-3α-hydroxy-5β-pregnan-20-one,3β-(4'-hydroxybutnyl)-3α-hydroxy-5β-pregnan-20-one,3β-(4'-hydroxybutynyl)-3α-hydroxy-5α-pregnan-20-one,3α-hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one,3α-hydroxy-3β-methyl-21-(1',2',4'-triazolyl)-5α-pregnan-20-one,3β-(4'-acetoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(4'-acetylphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one,3β-(4'-carboxyphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-oneethylester,3β-(4'-carboxyphenylethynyl)-3α-hydroxy-5α-pregnan-20-oneethylester,3β-[4'-(N,N-diethylcarboxamido)phenyl]ethynyl-3α-hydroxy-5.beta.-pregnan-20-one,3α-hydroxy-3β-[5-oxo-1-hexynyl]-5β-pregnan-20-one,3α-hydroxy-3β-[5'-oxo-1'-hexynyl]-5β-pregnan-20-one cyclic5'-(1,2-ethanediyl acetal),3β-(5-cyano-1-pentynyl)-3α-hydroxy-5β-pregnan-20-one,3α-hydroxy-3β-(2-pyridyl)ethynyl-5β-pregnan-20-one,3β-(6-hydroxy-1-hexynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one 6'-hemisuccinatesodium salt, 3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one5'-hemisuccinate sodium salt,3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one 4'-hemisuccinatesodium salt, 3β-(4'-cyano-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(5'-acetoxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(4'-acetoxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(4'-acetoxy-1'-butynyl)-3α-hydroxy-5α-pregnan-20-one,3β-(6'-acetoxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one,3α-hydroxy-3β-[3-(2'-propynyloxy)-1-propynyl]-5β-pregnan-20-one,3α-hydroxy-3β-(3-methoxy-1-propynyl)-5β-pregnan-20-one,3α-hydroxy-3β-(3-methoxy-1-propynyl)-5α-pregnan-20-one,3α-hydroxy-3β-[3-(4'-pyridinyloxy)-1-propynyl]-5β-pregnan-20-one,3α-hydroxy-3β-[3-(1'H-1,2,3-triazol-1'-yl)-1-propynyl]-5β-pregnan-20-one,3α-hydroxy-3β-[3-(2'H-1,2,3-triazol-2'-yl)-1-propynyl]-5β-pregnan-20-one,3α-hydroxy-3β-(2'-thienyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(3'-phenyl-1'-propynyl)-5β-pregnan-20-one,3α-hydroxy-3β-(3'-phenylpropyl)-5β-pregnan-20-one,3α-hydroxy-3β-[3-(1'H-pyrazol-1'-yl)-1-propynyl]-5β-pregnan-20-one,3β-(3'-acetylphenylethynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(3'-acetoxy-3'-propynyl)-3α-hydroxy-5β-pregnan-20-one,3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-pregnan-20-one,3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-19-nor-pregnan-20-one,3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1,2,3-triazol-2-yl)-5.beta.-19-norpregnan-20-one,3α-hydroxy-21-(1-imidazolyl)-5α-pregnan-20-one, sodiumS-(3α-hydroxy-3β-methyl-5α-pregnan-20-on-21-yl)thiosulfate, sodiumS-(3α-hydroxy-3β-methoxymethyl-5α-pregnan-20-on-21-yl)thiosulfate,sodium S-(3α-hydroxy-5β-pregnan-20-on-21-yl)thiosulfate, sodiumS-(3α-hydroxy-3β-trifluoromethyl-5β-pregnan-20-on-21-yl)thiosulfate,sodiumS-[3α-hydroxy-3β-(4'-hydroxybutynyl)-5β-pregnan-20-on-21-yl]thiosulfate,sodiumS-(3α-hydroxy-5α-pregnan-20-on-21-yl)thiosulfate, and3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one,3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one,3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt, and3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one21-hemisuccinate sodium salt.

The more preferred neuroactive steroids include3β-(4'acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one,3β-(4'-carboxyphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one ethyl ester,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-carboxylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one ethyl ester,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5β-19-norpregnan-20-one,3β-(4'-carboxylphenyl)ethynyl-3α-hydroxy-5β-19-norpregnan-20-oneethylester,3β-(4'-dimethylaminophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3.alpha.-hydroxy-3β-(4'-methoxyphenyl)ethynyl-5β-pregnan-20-one,3β-(4'-trifluoromethylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-chlorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-[4'(R/S)-hydroxypentynyl]-3α-hydroxy-5β-pregnan-20-one,3β-(4'-hydroxybutynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-hydroxybutynyl)-3α-hydroxy-5α-pregnan-20-one;3α-hydroxy-3β-[3-(2'H-1,2,3-triazol-2'-yl)-1-propynyl]-5β-pregnan-20-one;3α-hydroxy-21-(1-imidazolyl)-5β-pregnan-20-one,3β-(4'acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one,3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one,3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt, and3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one21-hemisuccinate sodium salt.

The especially preferred neuroactive steroids include3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-carboxylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one ethyl ester,3β-(4'-carboxylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one ethyl ester,3β-(4'-dimethylaminophenyl)ethynyl-5β-pregnan-20-one,3β-(4'-biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-hydroxybutynyl)-3α-hydroxy-5β-pregnan-20-one3β-(4'-hydroxybutynyl)-3α-hydroxy-5α-pregnan-20-one;3α-hydroxy-3β-[3-(2'H-1,2,3-triazol-2'-yl)-1-propynyl]-5β-pregnan-20-one;3α-hydroxy-21-(1-imidazolyl)-5β-pregnan-20-one,3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one,3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one,3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt,3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one21-hemisuccinate sodium salt and3β-[4'(R/S)-hydroxypentynyl]-3α-hydroxy-5β-pregnan-20-one.

Synthetic Methods

The compounds according to the invention may be prepared by anyconvenient method, e.g. using conventional techniques such as aredescribed in "Steroid Reactions," Djerassi, published in 1963 byHolden-Day, Inc., San Francisco or "Organic Reactions in SteroidChemistry", Fried and Edwards, published in 1972 by VanNostrand-Reinhold Co., New York.

General Methods

20-hydroxy pregnanes were prepared by the reduction of 20-keto pregnaneswith conventional reducing agents.

21-Hemisuccinates were prepared from pregnan-20-one derivatives whichwere first brominated with molecular bromine to obtain the corresponding21-bromo pregnanes. The bromo compounds were then reacted with variousdioic acids, such as succinic acid, in the presence of an amine to yield21-hydroxy esters. The resulting esters from the dioic acids were thenconverted to their sodium salts by conventional means.

21-Oxygenated compounds of this type may be prepared by a reactionsequence in which a pregnan-20-one is oxidized with lead tetraacetate togive a 21-acetoxy derivative, hydrolysis of the acetate to give a21-alcohol, and acylation with an appropriate carboxylic acidderivative, for example, an anhydride or acid chloride or other reagentcapable of replacing the hydrogen of the hydroxyl group, such asmethanesulfonyl chloride.

Pregn-17-enes may be formed by the reaction of a 17-ketosteroid with aWittig reagent such as the ylide derived from treatment of an-propyltriphenylphosphonium bromide with a strong base such aspotassium t-butoxide.

EXAMPLE 1 3α-Hydroxy-3β-(2'-phenylethyl)-5β-pregnan-20-one

A solution of 3α-hydroxy-3β-phenylethynyl-5β-pregnan-20-one (44 mg) wasdissolved in EtOAc (12 mL), Pd/C (5%, 12 mg) was added and the mixturewas hydrogenated at 400 Kpa pressure overnight at rt. Filtration of thecatalyst followed by evaporation of the solvent yielded the crudeproduct, which was purified by chromatography over silica gel to isolatethe pure title compound (33 mg); mp 153-154° C.; TLC R_(f)(hexane:acetone 7:3)=0.4.

EXAMPLE 2

3α-(3',4'-Dimethoxyphenylethynyl)-3β-hydroxy-5β-pregnan-20-one and3β-(3',4'-Dimethoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 2,2-dibromo-1-(3',4'-dimethoxyphenyl)ethene (prepared bythe Wittig reaction of 3,4-dimethoxybenzaldehyde with carbontetrabromide in the presence of triphenyl phosphine) (966 mg, 3 mmol) indry THF (15 mL) was treated under N₂ with n-BuLi (2.5 M in THF, 6 mmol,2.4 mL) at -78° C. The mixture was stirred at this temperature for 2hours and a solution of 5β-pregnan-3,20-dione cyclic 20-(1,2-ethanediylacetal) (720 mg, 2 mmol) in dry THF (10 mL) was added dropwise over aperiod of 30 min. After stirring the resulting mixture at -78° C. for 2hr, the cooling bath was removed and the stirring was continued at rtfor another hr. It was then quenched with 2 N HCl solution (1 mL) at-10° C. The solvent was removed and the residue was then dissolved inacetone (25 mL). After adding 2 N HCl (10 mL) the solution was stirredat rt for 2 hr. Sat. NaHCO₃ soln. was added to neutralize the acid. Thesolvents were removed and the residue was extracted with EtOAc. Theorganic layer was washed with water, dil. NaHCO₃ soln., water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (1.2 g). This crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with the toluene:acetone mixture (96:4) gave aphenylacetylene compound, which was not characterized. Further elutionwith the same solvent yielded3α-(3',4'-dimethoxyphenylethynyl)-3β-hydroxy-5β-pregnan-20-one (120 mg)as a first fraction, and3β-(3',4'-dimethoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one as asecond fraction (430 mg); mp 82-88° C.

An analogous method was used to prepare:3β-(4'-methoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-chlorophenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(2'-methoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-biphenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-dimethylaminophenylethynyl)-3α-hydroxy-5β-pregnan-20-one; and3β-(4'-cyanophenylethynyl)-3α-hydroxy-5β-pregnan-20-one.

EXAMPLE 3

3β-(3',4'-Dimethoxyphenylethyl)-3α-hydroxy-5β-pregnan-20-one

A mixture of Pd/C (5%, 28 mg) and EtOAc (12 mL) was presaturated withhydrogen by stirring it under hydrogen for 10 min. A solution of3β-(3',4'-dimethoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one (185 mg)in EtOAc (5 mL) was then added and the mixture was hydrogenated at 300Kpa pressure overnight at rt. Filtration of the catalyst followed byevaporation of the solvent yielded the crude product, which was purifiedby chromatography over silica gel (hexane:acetone 4:1) to isolate thepure title compound (135 mg); TLC R_(f) (hexane:acetone 4:1)=0.14.

EXAMPLE 4

3β-(4'-Nitrophenylethynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 2,2-dibromo-1-(4-nitrophenyl)ethene (prepared by theWittig reaction of 4-nitrobenzaldehyde with carbon tetrabromide in thepresence of triphenyl phosphine) (296 mg, 1 mmol) in dry THF (20 mL) wastreated under N₂ with n-BuLi (2.5 M in THF, 2 mmol, 0.8 mL) at -95° C.The mixture was stirred at -80 to -100° C. for 0.5 hr and then asolution of 5β-pregnan-3,20-dione cyclic 20-(1,2-ethanediyl acetal) (120mg, 0.5 mmol) in dry THF (10 mL) was added dropwise over a period of 10min. After stirring the resulting mixture at -80° C. for 1 hr, and thenat 0° C. for 1 more hr it was quenched with NH₄ Cl solution (3 mL). Thesolvent was removed and the residue was then dissolved in acetone (25mL). After adding 2 N HCl (10 mL) the solution was stirred at rt for 1hr. Saturated NaHCO₃ soln. was added to neutralize the acid. Thesolvents were removed and the residue was extracted with CH₂ Cl₂. Theorganic layer was washed with water, and brine. After drying over anhyd.MgSO₄ the solution was filtered and evaporated to yield the crudeproduct (400 mg). This crude product was then dissolved in a smallamount of CH₂ Cl₂ and poured on a column of silica get. Elution withtoluene:acetone mixture (96:4) gave the title compound as a brown solid(70 mg); TLC R_(f) (toluene:acetone 95:5)=0.18.

EXAMPLE 5

3β-Hydroxy-3α-phenyl-5β-pregnan-20-one and3α-hydroxy-3β-phenyl-5β-pregnan-20-one

A solution of 5β-pregnan-3,20-dione cyclic 20-(1,2-ethanediyl acetal)(720 mg, 2 mmol) in 15 ml of dry THF was treated with phenyl magnesiumbromide (3 M in THF, 6 mmol, 2 mL) at -70° C. After stirring the mixtureat this temperature for 3 hr and then at rt for 2 hr, it was quenchedwith 2 N HCl (1 mL). The solvent was removed and the residue wasdissolved in acetone (20 mL). After adding 1 N HCl (5 mL) the solutionwas stirred at rt for 15 hr. The solvents were removed and the residuewas extracted with CH₂ Cl₂. The organic layer was washed with water,dil. NaHCO₃ soln., water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to yield the crude product (1.3 g).This crude product was then dissolved in a small amount of CH₂ Cl₂ andpoured on a column of silica gel. Elution with toluene:acetone mixture(95:5) gave a 3α-phenyl-3β-hydroxy-5β-pregnan-20-one (420 mg) as a firstfraction. Further elution with the same solvent mixture yielded3β-phenyl-3α-hydroxy-5β-pregnan-20-one (185 mg), m.p. 182-184° C.

EXAMPLE 6

3β-Hydroxy-3α-benzyl-5β-pregnan-20-one and3α-hydroxy-3β-benzyl-5β-pregnan-20-one

A solution of benzyl magnesium bromide (2 M in THF, 2 mmol, 1 mL) wasdiluted with THF (15 mL) and was treated dropwise with a solution of5β-pregnan-3,20-dione cyclic 20-(1,2-ethanediyl acetal) (360 mg, 1 mmol)in dry THF (15 mL) at -60° C. After stirring the mixture at thistemperature for 1 hr and then at rt for 15 hr, it was quenched with 2 NHCl (1 mL). The solvent was removed and the residue was dissolved inacetone (20 mL). After adding 1 N HCl (5 mL) the solution was stirred atrt for 30 min. It was neutralized with 2 N NaOH. The precipitated solidwas collected by filtration, washed with water and dried to yield3β-hydroxy-3α-benzyl-5β-pregnan-20- one (238 mg). The filtrate wasextracted with EtOAc. The organic layer was washed with water, dil.NaHCO₃ soln., water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to give the crude product (160 mg).This crude product was then dissolved in a small amount of CH₂ Cl₂ andpoured on a column of silica gel. Elution with toluene:acetone mixture(95:5) gave 3β-hydroxy-3α-benzyl-5β-pregnan-20-one (40 mg) as a firstfraction. Further elution with the same solvent mixture yielded3α-hydroxy-3β-benzyl-5β-pregnan-20-one (30 mg), which was crystallizedfrom hexane:CH₂ Cl₂ (4:1) as colorless rods (15 mg); m.p. 133-141° C.;TLC R_(f) (toluene:acetone 9:1)=0.5.

EXAMPLE 7

3β-[3'(R/S)-Hydroxybutynyl]-3α-hydroxy-5β-pregnan-20-one

A solution of 3 (R/S)-hydroxybutyne (0.470 mL, 6 mmol) in dry THF (15mL) was treated with n-BuLi (2.5 M in THF, 12 mmol, 4.8 mL) at -70° C.After stirring the mixture at this temperature for 0.5 hr, a solution of5β-pregnan-3,20-dione cyclic 20-(1,2-ethanediyl acetal) (1.08 g, 3 mmol)in dry THF (30 mL) was added and the mixture was stirred at -78° C. for1 hr. The cooling bath was removed and the mixture was stirred at rt foranother 1.5 hr. It was then quenched with NH₄ Cl solution (3 mL). Thesolvent was removed and the residue was the dissolved in acetone (10mL). After adding 2 N HCl (5 mL), the solution was stirred at rt for 1hr. Saturated NaHCO₃ soln. was added to neutralize the acid. Thesolvents were removed and the residue was extracted with EtOAc. Theorganic layer was washed with water, dil. NaHCO₃ soln., water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (1.4 g). This crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with toluene:acetone mixture (85:15 ) gave3β-[3'(RS)-hydroxybutynyl]-3α-hydroxy-5β-pregnan-20-one (145 mg) as acolorless solid; TLC R_(f) (toluene:acetone 4:1)=0.24.

An analogous method was used to prepare:3β-[4'(R/S)-hydroxypentynyl]-3α-hydroxy-5β-pregnan-20-one.

EXAMPLE 8

3β-(4'-Acetylphenylethynyl)-3α-hydroxy-5α-pregnan-20-one

A solution of 4-iodoacetophenone (95 mg, 0.39 mmol),3β-ethynyl-3α-hydroxy-5α-pregnan-20-one (106 mg, 0.3 mmol) in drydegassed pyrrolidine (3 mL) was stirred under argon at rt.Bis(triphenylphosphine)palladium(II) dichloride (5 mg) and CuI (5 mg)were added and the mixture was stirred at rt for 15 hr. The TLC showed100% conversion of the starting material, hence, the mixture wasquenched with NH₄ Cl solution (15 mL) and was extracted with EtOAc. Theorganic layer was washed with water, dil. NaHCO₃ soln., water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (150 mg). This crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with hexane:acetone mixture (4:1) afforded3β-(4'-acetylphenylethynyl)-3α-hydroxy-5α-pregnan-20-one (35 mg) as acolorless solid; TLC R_(f) (hexane:acetone 7:3)=0.4.

An analogous method was used to prepare:3α-hydroxy-3β-(4'-trifluoromethylphenylethynyl)-5β-pregnan-20-one;3β-(4'-acetylphenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3α-hydroxy-3β-(4'-methylphenylethynyl)-5β-pregnan-20-one;3α-hydroxy-3β-(4'-acetoxyacetylphenylethynyl)-5β-pregnan-20-one;3β-(3'-hydroxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(2',4'-difluorophenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(pentafluorophenylethynyl)-3α-hydroxy-5β-pregnan-20-one; and3α-hydroxy-3β-(4'-carboxyphenylethynyl)-5β-pregnan-20-one ethyl ester.

EXAMPLE 9

3αHydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one

3α-Hydroxy-21-bromo-5β-pregnan-20-one

To a flask containing a solution of 3α-hydroxy-5β-pregnan-20-one (5.15g, 16.5 mmol)in methanol (100 mL) was added a solution of bromine (1.1mL) in methanol (30 mL) dropwise in such a rate to maintain the browncolor of the bromine until this color was persistent. Then water (200mL) was added and the mixture was extracted with CH₂ Cl₂ (3×100 mL). Thecombined extracts were dried over Na₂ SO₄. Removal of the solventresulted in the product as a foamy white solid (6.63 g). Other21-bromo-pregnan-20-ones(3β-ethynyl-3α-hydroxy-21-bromo-5β-pregnan-20-one,3β-methyl-3α-hydroxy-21-bromo-5α-pregnan-20-one and3α-hydroxy-3β-trifluoromethyl-12-bromo-5β-19-norpregnan-20-one) weresynthesized using the same method.

3α-Hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one

A mixture of 3α-hydroxy-21-bromo-5β-pregnan-20-one (0.86 g) andimidazole (0.37 g) in CH₃ CN (12 mL) was heated under Ar to reflux for 1h and cooled to 25° C. It was then poured into a separatory funnelcontaining NH₄ Cl solution (100 mL, aq. sat.) and the product wasextracted with EtOAc )3×50 mL). The combined organics were dried overNa₂ SO₄ and the solvent was removed in vacuo. The pure product (0.59 g,42%) was isolated by flash column chromatography.

The compounds 3α-hydroxy-21-(1'-benzimidazolyl)-5β-pregnan-20-one,3α-hydroxy-21-[1H-(4-methyl-5-carbethoxyl)imidazol-1-yl)-5β-pregnan-20-one ethylester,3α-hydroxy-21-(1'-imidazolyl)-5α-pregnan-20-one,3β-ethynyl-3α-hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one,3α-hydroxy-21-(1 H-3,5-dimethylpyrazolyl)-5β-pregnan-20-one,3α-hydroxy-21-(1'-imidazolyl)-3β-methyl-5α-pregnan-20-one,3α-hydroxy-21-(1'-pyrazolyl)-5α-pregnan-20-one,3β-ethynyl-3α-hydroxy-21-(1'-pyrazolyl)-5β-pregnan-20-one,21-(1'-benzimidazolyl)-3α-hydroxy-3β-methyl-5α-pregnan-20-one,3α-hydroxy-21-(1'-pyrazolyl)-3β-methyl-5α-pregnan-20-one,3α-hydroxy-21-(pyrazol-1-yl)-5β-pregnan-20-one, 3α-hydroxy-21-[1H-(2-methyl)imidazol-1-yl)-5β-pregnan-20-one, 3α-hydroxy-21-[1H-(2'-formyl)imidazol-1-yl)]-5β-pregnan-20-one, 3α-hydroxy-21-(1H-imidazol-1-yl)-3β-trifluoromethyl-5β-19-norpregnan-20-one, and3α-hydroxy-21-(pyrazol-1-yl)-3β-trifluoromethyl-5β-19-norpregnan-20-onewere synthesized according to Example 9.

EXAMPLE 10

3α-Hydroxy-3β-methyl-21-(1',2',4'-triazolyl)-5α-pregnan-20one:

To a solution of 1,2,4-triazole (146 mg) in THF (15 mL) under Ar wasadded NaH (56 mg) and the mixture obtained was stirred at 25° C. for 20min. Then a solution 3β-methyl-3α-hydroxy-21-bromo-5α-pregnan-20-one(300 mg) in THF was added and the mixture thus obtained was stirred for5 hr. It was then poured into a separatory funnel containing water (40mL) and the product was extracted with CH₂ Cl₂ (3×50 mL). The combinedorganics were dried over Na₂ So₄ and the solvent was removed in vacuo.The pure product (187 mg, 64%) was isolated by flash columnchromatography.

3α-Hydroxy-21-(2' H-1,2,3,4-tetrazol-2'-yl)-5β-pregnan-20-one,3α-hydroxy-21-(2 H-1,2,3-triazol-2-yl)-5β-pregnan-20-one,3α-hydroxy-21-(9' H-purin-9'-yl)-5β-pregnan-20-one,3α-hydroxy-3β-methyl-21-(2' H-1',2',3'-triazol-2'-yl)-5α-pregnan-20-one,3β-ethynyl-3α-hydroxy-21-(1',2',4'-triazolyl)-5β-pregnan-20-one,3α-hydroxy-3β-methyl-21-(1',2',3'-triazol-1'-yl)-5α-pregnan-20-one,3α-hydroxy-21-(1',2',4'-triazol-1-yl)-5β-pregnan-20-one,3α-hydroxy-21-(1' H-1,2,3,4-tetrazol-1'-yl)-5β-pregnan-20-one,3α-hydroxy-21-[1 H-(4-nitro)imidazol-1-yl)-5β-pregnan-20-one,3α-hydroxy-21-(7' H-purin-7'-yl)-5β-pregnan-20-one, 3α-hydroxy-21-[1H-(4',5'-dicyano)imidazol-1-yl)]-5β-pregnan-20-one,3α-hydroxy-21-(1'-1,2,4-triazol-1-yl)-3β-trifluoromethyl-5.beta.-19-norpregnan-20-one,and 3α-hydroxy-21-[1H-(4',5'-dichloro)imidazol-1-yl)]-5β-pregnan-20-one, were synthesizedaccording to the procedures set forth in Example 10.

EXAMPLE 11

3β-(4'-Acetoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one

a. 3β-(4'-Hydroxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 2,2-dibromo-1-(4-hydroxyphenyl)ethene (prepared by theWittig reaction of 4-hydroxybenzaldehyde with carbon tetrabromide in thepresence of triphenyl phosphine) (1.25 mg, 4.5 mmol) in dry THF (25 mL)was treated under N₂ with n-BuLi (2.5 M in THF, 13.5 mmol, 5.4 mL) at-70° C. The mixture was then stirred at -70° C. temp. for 0.5 hr, and asolution of 5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal)(810 mg, 2.25 mmol) in dry THF (25 mL) was added dropwise over a periodof 10 min. After stirring the resulting mixture at -78° C. for 30 min,the cooling bath was removed and the stirring was continued at rt foranother hr. It was then quenched with sat. NH₄ Cl solution (4 mL) at-10° C. The solvent was removed and the residue was then dissolved inacetone (25 mL). After adding 2 N HCl (6 mL) the solution was stirred atrt for 15 min. Sat. NaHCO₃ soln. was added to neutralize the acid. Thesolvent was removed under reduced pressure and the crude product (1.3 g)was used as such for the next step.

b. 3β-(4'-Acetoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one

The crude product from the above step was dissolved in CH₂ Cl₂ (5 mL)and pyridine (3 mL). The resulting solution was added to a ice-coldmixture of acetyl chloride (3 mL) and pyridine (3 mL). The mixture wasstirred at 0° C. for 30 min. and was poured into ice (50 g). 2 N HCl (10mL) was added and the mixture was diluted with more CH₂ Cl₂. The organiclayer was separated, washed with water, brine, and dried over anhyd.MgSO₄. Removal of solvent gave a crude solid (2 g) which was purified bycolumn chromatography over silica gel. Elution with toluene:acetonemixture (95:5) gave3α-(4'-acetoxyphenylethynyl)-3β-hydroxy-5β-pregnan-20-one (150 mg).Further elution with the same solvent mixture yielded3β-(4'-acetoxphenylethynyl)-3α-hydroxy-5β-pregnan-20-one (530 mg); m.p.171-176° C.; TLC R_(f) (hexane:acetone 7:3)=0.41.

EXAMPLE 12

3β-(4'-Acetylphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one

A solution of 4-iodoacetophenone (60 mg, 0.24 mmol),3β-ethynyl-3α-hydroxy-19-nor-5β-pregnan-20-one (80 mg, 0.24 mmol) in drydegassed triethylamine (0.5 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)-palladium(II)dichloride (5 mg) and CuI (5 mg)were added and the mixture was stirred at this temp. for 45 min. CH₂ Cl₂(4 mL) was added and the mixture was stirred at 23° C. for 3 hr. The TLCshowed 100% conversion of the starting material, hence, the solvent wasremoved and the residue was purified by chromatography on silica gel.Elution with hexane:acetone (4:1) gave3β-(4'-acetylphenyl-ethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one (30 mg)as a colorless solid; mp 65-67° C., TLC R_(f) (hexane:acetone 4:1)=0.12.

EXAMPLE 13

3β-(4'-Carboxyphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one ethylester

A solution of ethyl 4-iodobenzoate (70 mg, 0.24 mmol) and3β-ethynyl-3α-hydroxy-19-nor-5β-pregnan-20-one (80 mg, 0.24 mmol) in drydegassed triethylamine (1 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)-palladium(II)dichloride (5 mg) and CuI (5 mg)were added and the mixture was stirred at this temp. for 1 hr. CH₂ Cl₂(4 mL) was added and the mixture was stirred at 23° C. for 3 hr. The TLCshowed 100% conversion of the starting material, hence, the solvent wasremoved and the residue was purified by chromatography on silica gel.Elution with hexane:acetone (4:1) gave3β-(4'-carboxyphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one ethylester (22 mg) as a colorless solid; mp 164-166° C., TLC R_(f)(hexane:acetone 4:1)=0.27.

EXAMPLE 14

3β-(4'-Carboxyphenylethynyl)-3α-hydroxy-5α-pregnan-20-one ethyl ester

A solution of ethyl 4-iodobenzoate (83 mg, 0.3 mmol),3β-ethynyl-3α-hydroxy-5α-pregnan-20-one (103 mg, 0.3 mmol) in drydegassed triethylamine (1 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)-palladium(II)dichloride (5 mg)and CuI (5 mg)were added and the mixture was stirred at this temp. for 1 hr. CH₂ Cl₂(4 mL) was added and the mixture was stirred at 23° C. for 1.5 hr. TheTLC showed 100% conversion of the starting material, hence, the solventwas removed and the residue was purified by chromatography on silicagel. Elution with hexane:acetone (4:1) gave3β-(4'-carboxyphenylethynyl)-3α-hydroxy-5α-pregnan-20-one ethyl ester(10 mg) as a colorless solid; map 190-192° C., TLC R_(f) (hexane:acetone4:1)=0.27.

EXAMPLE 15

3β-[4'-(N,N-diethylcarboxamido)phyenyl]ethynyl-3α-hydroxy-5.beta.-pregnan-20-one

A solution of 4-(N,N-diethylcarboxamido)iodobenzene (91 mg, 0.3 mmol),3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (103 mg, 0.3 mmol) in drydegassed triethylamine (1 mL) was stirred under argon at 23° C.Bis(triphenyl-phosphine)palladium(II)dichloride (5 mg) and CuI (5 mg)were added and the mixture was stirred at this temp. for 1 hr. CH₂ Cl₂(4 mL) was added and the mixture was stirred at 23° C. for 0.5 hr. TheTLC showed 100% conversion of the starting material, hence, the solventwas removed and the residue was purified by chromatography on silicagel. Elution with hexane:acetone (3:1) gave3β-[4'-(N,N-diethylcarboxamido)phenyl]ethynyl-3α-hydroxy-5.alpha.-pregnan-20-oneethyl ester (18 mg) as a colorless solid; TLC R_(f) (hexane:acetone3:1)=0.22.

EXAMPLE 16

3α-Hydroxy-3β-[5-oxo-1-hexynyl]-5β-pregnan-20-one cyclic (1,2-ethanediylacetal)

A solution of 1-hexyn-5-one cyclic (1,2-ethanediyl acetal) (493 mg, 3.52mmol) in dry THF (15 mL) was treated with n-BuLi (2.5 M in THF, 3 mmol,1.2 mL) at -60° C. After stirring the mixture at -78° C. for 0.5 hr, asolution of 5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal)(360 mg, 1 mmol) in THF (15 mL) was added and the mixture was stirred at-78° C. for 1 hr. The cooling bath was removed and the mixture wasquenched with NH₄ Cl solution (3 mL). The solvent was removed and theresidue was then dissolved in acetone (40 mL). After adding 1 N HCl (4mL) the solution was stirred at rt for 15 min. Sat. NaHCO₃ soln. wasadded to neutralize the acid. The solvents were removed and the residuewas extracted with EtOAc. The organic layer was washed with water, dil.NaHCO₃ soln., water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to yield the crude product (700mg). This crude product was then dissolved in a small amount of CH₂ Cl₂and poured on a column of silica gel. Elution with toluene:acetonemixture (93:7) gave 3α-hydroxy-3β-[5-oxo-1-hexynyl]-5β-pregnan-20-onecyclic (1,2-ethanediyl acetal) (210 mg) as a colorless solid; mp130-133° C.; TLC R_(f) (toluene:acetone 9:1)=0.33.

EXAMPLE 17

3α-Hydroxy-3β-[5-oxo-1-hexynyl]-5β-pregnan-20-one

3α-Hydroxy-3β-[5-oxo-1-hexynyl]-5β-pregnan-20-one cyclic (1,2-ethanediylacetal) (95 mg) was dissolved in acetone (5 mL). After adding 2 N HCl (1mL) the solution was stirred at rt for 3 hr. Sat. NaHCO₃ soln. was addedto neutralize the acid. The solvents were removed and the residue wasextracted with EtOAc. The organic layer was washed with water, water,and brine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude title product (100 mg), which was thencrystallized from hexane-acetone as colorless rods, yield 63 mg; mp104-106° C.; TLC R_(f) (hexane:acetone 7:3)=0.27.

An analogous method was used to prepare3α-hydroxy-3β-[6-oxo-1-heptynyl]-5β-pregnan-20-one, using 1-heptyn-6-onecyclic 6-(1,2-ethanediyl acetal).

EXAMPLE 18

3β-(5-Cyano-1-pentynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 5-cyanopentyne (0.84 mL, 8 mmol) in dry THF (20 mL) wastreated with n-BuLi (2.5 M in THF, 7.8 mmol, 3.2 mL) at -70° C. Afterstirring the mixture at -75° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (720 mg, 2mmol) in THF (20 mL) was added and the mixture was stirred at -78° C.for 0.5 hr. The cooling bath was removed and the mixture was quenchedwith NH₄ Cl solution (3 mL). The solvent was removed and the residue wasthen dissolved in acetone (40 mL). After adding 1 N HCl (4 mL) thesolution was stirred at rt for 15 min. Sat. NaHCO₃ soln. was added toneutralize the acid. The solvents were removed and the residue wasextracted with EtOAc. The organic layer was washed with water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (1.55 g). The crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with toluene:acetone mixture (95:5) gave3α-(5-cyano-1-pentynyl)-3β-hydroxy-5β-pregnan-20-one (170 mg) as a firstfraction. Further elution with the same solvent mixture yielded3β-(5-cyano-1-pentynyl)-3α-hydroxy-5β-pregnan-20-one (480 mg) as acolorless solid; mp 134-136° C.; TLC R_(f) (hexane:acetone 7:3)=0.3.

An analogous method was used to prepare3β-(4-cyano-1-butynyl)-3α-hydroxy-5β-pregnan-20-one.

EXAMPLE 19

3α-Hydroxy-3β-(2-pyridyl)ethynyl-5β-pregnan-20-one

A solution of 2-ethynylpyridine (270 mg, 2.6 mmol) in dry THF (15 mL)was treated with n-BuLi (2.5 M in THF, 2.5 mmol, 1 mL) at -60° C. Afterstirring the mixture at -78° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (170 mg, 0.47mmol) in THF (15 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the mixture was quenched withNH₄ Cl solution (3 mL). The solvent was removed and the residue was thendissolved in acetone (25 mL). After adding 2 N HCl (2 mL) the solutionwas stirred at rt for 15 min. Sat. NaHCO₃ soln. was added to neutralizethe acid. The solvents were removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product (360 mg). This crude product was then dissolved in a smallamount of CH₂ Cl₂ and poured on a column of silica gel. Elution withtoluene:acetone mixture (95:5) gave the unreacted ethynylpyridine as afirst fraction. Further elution with the same solvent mixture yielded3β-(2-pyridyl)ethynyl-3α-hydroxy-5β-pregnan-20-one (170 mg) as acolorless solid; mp 192-195° C.; TLC R_(f) (toluene:acetone 87:13)=0.21.

EXAMPLE 20

3β-(6-hydroxy-1-hexynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 5-hexyn-1-ol (1.35 mL, 12 mmol) in dry THF (15 mL) wastreated with n-BuLi (9.6 mL, 2.5 M in THF, 24 mmol) at -65° C. Afterstirring the mixture at -78° C. for 0.5 hr, a solution of5β-pregnan-3,20 -dione, cyclic 20-(1,2-ethanediyl acetal) (1.08 g, 3mmol) in THF (20 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the stirring was continued atrt for 45 min. The mixture was then quenched with NH₄ Cl solution (5mL). The solvent was removed the residue was extracted with EtOAc. Theorganic layer was washed with water, dil. NaHCO₃ soln., water, andbrine. After drying over anhyd. MgSO₄. The solution was filtered andevaporated to yield the crude product (1.90 g). This crude product wasthen crystallized from EtOAc to yield the pure product as colorless rods(890 mg). this was then dissolved in acetone (120 mL). After adding 2 NHCl (3 mL) the solution was stirred at rt for 15 min. Sat. NaHCO₃ soln.was added to neutralize the acid. The solvents were removed and theresidue was extracted with EtOAc. The organic layer was washed withwater, and brine. After drying over anhyd. MgSO₄, the solution wasfiltered and evaporated to yield the crude product. This crude productwas then dissolved in a small amount of CH₂ Cl₂ and poured on a columnof silica gel. Elution with toluene:acetone mixture (95:5) gave theunreacted hexynol as a first fraction. Further elution with the samesolvent mixture yielded3α-(6-hydroxy-1-hexynyl)-3β-hydroxy-5β-pregnan-20-one (60 mg), and then3β-(6-hydroxy-1-hexynyl)-3α-hydroxy-5β-pregnan-20-one (620 mg) as acolorless solid; mp 132-134° C.; TLC R_(f) (hexane:acetone 7:3)=0.23.

EXAMPLE 21

3β-(6'-Hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one 6'-hemisuccinatesodium salt

a. 3β-(6'-Hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one6'-hemisuccinate

A solution of 3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one(600 mg, 1.45 mmol) in pyridine (5 mL) was treated with succinicanhydride (600 mg, 6 mmol) and 4-(N,N-dimethyl)aminopyridine (20 mg).The mixture was heated to 70-75° C. for 1.25 hr. The tlc showed 100%conversion. It was cooled to rt and was poured into ice-2 N HCl. Theorganics were extracted with EtOAc. The organic layer was washed with0.2 N HCl, water, and brine. After drying over anhyd. MgSO₄ the solutionwas filtered and evaporated to yield the crude product. This crudeproduct was then dissolved in a small amount of CH₂ Cl₂ and poured on acolumn of silica gel. Elution with hexane:acetone mixture (7:3) gave3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one 6'-hemisuccinate(700 mg); TLC R_(f) (hexane:acetone:AcOH 70:30:0.5)=0.21.

b. 3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5βpregnan-20-one6'-hemisuccinate sodium salt

A mixture of the above hemisuccinate (400 mg), NaHCO₃ (68 mg), water (8mL), and CH₂ Cl₂ (1 mL) was stirred at rt for 15 min. The solvent wasremoved and the residue was freeze-dried to yield the sodium salt as acolorless solid (400 mg).

EXAMPLE 22

3β-(5'-Hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 4-pentyn-1-ol (1.1 mL, 12 mmol) in dry THF (15 mL) wastreated with n-BuLi (9.9 mL, 2.5 M in THF, 24.5 mmol) at -65° C. Afterstirring the mixture at -78° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (1.08 g, 3mmol) in THF (20 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the stirring was continued atrt for 45 min. The mixture was then quenched with NH₄ Cl solution (5mL). The solvent was removed the residue was then dissolved in acetone(30 mL). After adding 2 N HCl (7 mL) the solution was stirred at rt for15 min. Sat. NaHCO₃ soln. was added to neutralize the acid. The solventswere removed and the residue was extracted with EtOAc. The organic layerwas washed with water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to yield the crude product. Thiscrude product was then dissolved in a small amount of CH₂ Cl₂ and pouredon a column of silica gel. Elution with toluene:acetone:EtOAc mixture(70:15:15) gave the unreacted pentynol as a first fraction. Furtherelution with the same solvent mixture yielded3α-(5'-hydroxy-1'-pentynyl)-3β-hydroxy-5β-pregnan-20-one (100 mg), andthen 3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one (650 mg)as a colorless solid; mp 160-163° C.; TLC R_(f) (toluene:acetone:EtOAc70:15:15)=0.28.

An analogus method was used to prepare:3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-19-norpregnan-20-one;3β-(4'-hydroxy-1'-hydroxy-1'-butynyl)-3α-hydroxy-5α-pregnan-20-one;3β-[4'(R/S)-hydroxy-1'-pentynyl]-3α-hydroxy-5α-pregnan-20-one;3β-[3'(R/S)-hydroxy-1'-butynyl]-3α-hydroxy-5α-pregnan-20-one; and3β-(3'-hydroxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one.

EXAMPLE 23

3β-(5'-Hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one5'-hemisuccinate sodium salt

a. 3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one5'-hemisuccinate

A solution of 3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one(350 mg, 0.87 mmol) in pyridine (3 mL) was treated with succinicanhydride (380 mg, 3.8 mmol) and 4-(N,N-dimethyl)aminopyridine (20 mg).The mixture was heated to 65-70° C. for 1 hr. The TLC showed 100%conversion. It was cooled to rt and was poured into ice-2 N HCl. Theorganics were extracted with EtOAc. The organic layer was washed with0.2 N HCl, water, and brine. After drying over anhyd. MgSO₄ the solutionwas filtered and evaporated to yield the crude product (900 mg). Thiscrude product was then dissolved in a small amount of CH₂ Cl₂ and pouredon a column of silica gel. Elution with hexane:acetone mixture (7:3)gave 3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one5'-hemisuccinate (350 mg); TLC R_(f) (hexane:acetone:AcOH70:30:0.5)=0.25.

b. 3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one5'-hemisuccinate sodium salt

A mixture of the above hemisuccinate (345 mg), NaHCO₃ (60 mg), water (5mL), THF (2 mL), and CH₂ Cl₂ (1 mL) was stirred at rt for 1 hr. Thesolvent was removed and the residue was freeze-dried to yield the sodiumsalt as a colorless solid (340 mg).

An analogous method was used to prepare hemisuccinate sodium salts from:3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-19-norpregnan-20-one;3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5α-pregnan-20-one;3β-[4'(R/S)-hydroxy-1'-pentynyl]-3α-hydroxy-5α-pregnan-20-one;3β-[3'(R/S)-hydroxy-1'-butynyl]-3α-hydroxy-5α-pregnan-20-one; and3β-(3'-hydroxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one.

EXAMPLE 24

3β-(5'-Acetoxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of pyridine (280 mg) in CH₂ Cl₂ (2 mL) was treated withacetyl chloride (280 mg) at 0-5° C. A solution of3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one (130 mg) in CH₂Cl₂ (3 mL) was added. The stirring was continued at 0° C. for 20 min.The TLC showed 100% conversion, hence, the mixture was poured into ice-2N HCl (20 g, 2 mL). The organics were extracted with EtOAc. The organiclayer was washed with 0.2 N HCl, water, and brine. After drying overanhyd. MgSO₄ the solution was filtered and evaporated to yield the crudeproduct. This crude product was then dissolved in a small amount of CH₂Cl₂ and poured on a column of silica gel. Elution with toluene:acetonemixture (9:1) gave3β-(5'-acetoxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one (100 mg); mp84-87° C.; TLC R_(f) (hexane:acetone 70:30)=0.38.

EXAMPLE 25

3β-(4'-Acetoxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of pyridine (280 mg) in CH₂ Cl₂ (2 mL) was treated withacetyl chloride (280 mg) at 10° C. A solution of3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one (110 mg) in CH₂Cl₂ (3 mL) was added. The stirring was continued at 10° C. for 30 min.The TLC showed 100% conversion, hence, the mixture was poured into ice-2N HCl (20 g, 3 mL). The organics were extracted with EtOAc. The organiclayer was washed with 0.2 N HCl, water, and brine. After drying overanhyd. MgSO₄ the solution was filtered and evaporated to yield the crudeproduct. This crude product was then dissolved in a small amount of CH₂Cl₂ and poured on a column of silica get. Elution with hexane:acetonemixture (4:1) gave3β-(4'-acetoxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one (92 mg); mp170-173° C.; TLC R_(f) (hexane:acetone 70:30)=0.3.

EXAMPLE 26

3β-(6'-Acetoxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of pyridine (2 mL) in CH₂ Cl₂ (10 mL) was treated with acetylchloride (2 mL) at 0° C. A solution of3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one (400 mg, 0.96mmol) in CH₂ Cl₂ (5 mL) was added. The stirring was continued at 0° C.for 20 min. The TLC showed 100% conversion, hence, the mixture waspoured into ice-2 N HCl (50 g, 11 mL). The organics were extracted withEtOAc. The organic layer was washed with 0.2 N HCl, water, and brine.After drying over anhyd. MgSO₄ the solution was filtered and evaporatedto yield the crude product (500 mg). This crude product was thendissolved in a small amount of CH₂ Cl₂ and poured on a column of silicagel. Elution with toluene:acetone mixture (95:5) gave3β-(6'-acetoxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one (130 mg); mp85-87° C.; TLC R_(f) (toluene:acetone 93:7)=0.2.

EXAMPLE 27

3α-Hydroxy-3β-[3-(2'-propynyloxy)-1-propynyl]-5β-pregnan-20-one

A solution of propargyl ether (0.3 mL, 3 mmol) in dry THF (10 mL) wastreated with n-BuLi (2.4 M in THF, 3 mmol, 1.25 mL) at -70° C. Afterstirring the mixture at -75° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (360 mg, 1mmol) in THF (10 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the mixture was quenched withNH₄ Cl solution (5 mL). The solvent was removed and the residue was thendissolved in acetone (40 mL). After adding 1 N HCl (4 mL) the solutionwas stirred at rt for 15 min. Sat. NaHCO₃ soln. was added to neutralizethe acid. The solvents were removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product. This crude product was then dissolved in a small amountof CH₂ Cl₂ and poured on a column of silica get. Elution withtoluene:acetone mixture (95:5) gave3β-Hydroxy-3α-[3-(2'-propynyloxy)-1-propynyl]-5β-pregnan-20-one (31 mg)as a first fraction. Further elution with the same solvent mixtureyielded 3α-hydroxy-3β-[3-(2'-propynyloxy)-1-propynyl]-5β-pregnan-20-one(255 mg) as a colorless solid; mp 103-106° C.; TLC R_(f)(toluene:acetone 95:5)=0.39.

Example 28 3α-Hydroxy-3β-(3-methoxy-1-propynyl)-5β-pregnan-20-one

A solution of methyl propargyl ether (0.25 mL, 3 mmol) in dry THF (10mL) was treated with n-BuLi (2.4M in THF, 2.9 mmol, 1.20 mL) at -70° C.After stirring the mixture at -75° C. for 0.5 hr, a solution of5-β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (185 mg, 0.5mmol) in THF (10 mL) was added and the mixture was stirred at -78° C.for 20 min. The cooling bath was removed and the mixture was quenchedwith NH₄ Cl solution (2 mL). The solvent was removed and the residue wasthen dissolved in acetone (25 mL). After adding 2N HCl (2 mL) thesolution was stirred at rt for 15 min. Sat. NaHCO₃ soln. was added toneutralize the acid. The solvents were removed and the residue wasextracted with EtOAc. The organic layer was washed with water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (250 mg). This crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with toluene:acetone mixture (93:7) gave3β-hydroxy-3α-(3-methoxy-1-propynyl)-5β-pregnan-20-one (19 mg) as afirst fraction. Further elution with the same solvent mixture yielded3α-hydroxy-3β-(3-methoxy-1-propynyl)-5β-pregnan-20-one (115 mg) as acolorless solid; mp 155-159° C.; TLC R_(f) (hexane:acetone)=0.25.

Example 293α-Hydroxy-3β-[3-(4'-pyridinyloxy)-1-propynyl]-5β-pregnan-20-one

A solution of propargyl 4-pyridyl ether (prepared according to (Thummelet al, J. Org. Chem. 1978, 43, 4882) (173 mg, 1.3 mmol) in dry THF (15mL) was treated with n-BuLi (2.5M in THF, 1.3 mmol, 0.52 mL) at -70° C.After stirring the mixture at -75° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (180 mg, 0.5mmol) in THF (15 mL) was added and the mixture was stirred at -78° C.for 20 min. The cooling bath was removed and the stirring was continuedat rt for 1 hr. The mixture was quenched with NH₄ Cl solution (2 mL).The solvent was removed and the residue was then dissolved in acetone(25 mL). After adding 2N HCl (2 mL) the solution was stirred at rt for20 min. Sat. NaHCO₃ soln. was added to neutralize the acid. The solventswere removed and the residue was extracted with EtOAc. The organic layerwas washed with water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to yield the crude product (250mg). This crude product was then dissolved in a small amount of CH₂ Cl₂and poured on a column of silica gel. Elution with CH₂ Cl₂ :acetonemixture (90:10) gave3α-hydroxy-3β-[3-(4'-pyridinyloxy)-1-propynyl]-5β-pregnan-20-one (145mg) as a colorless solid; mp 84-90° C.; TLC R_(f) (CH₂ Cl₂ :acetone85:15)=0.17.

Example 303α-Hydroxy-3β-[3-(1'H-1,2,3-triazol-1'-yl)-1-propynyl]-5β-pregnan-20-one

A solution of 1-(2-propynyl)-1H-1,2,3-triazole (prepared by the reactionof triazole with propargyl bromide) (77 mg, 0.72 mmol) in dry THF (10mL) was treated with n-BuLi (2.5M in THF, 0.72 mmol, 0.28 mL) at -70° C.After stirring the mixture at -75° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (130 mg, 0.36mmol) in THF (10 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the mixture was quenched withNH₄ Cl solution (1 mL). The solvent was removed and the residue was thendissolved in acetone (25 mL). After adding 2N HCl (2 mL) the solutionwas stirred at rt for 30 min. Sat. NaHCO₃ soln. was added to neutralizethe acid. The solvents were removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product. This crude product was then dissolved in a small amountof CH₂ Cl₂ and poured on a column of silica gel. Elution withtoluene:acetone mixture (85:15) gave3α-hydroxy-3β-[3-(1'H-1,2,3-triazol-1'-yl)-1-propynyl]-5β-pregnan-20-one(56 mg) as a colorless solid; mp 142-144° C.; TLC R_(f) (hexane:acetone7:3)=0.33.

Example 313α-Hydroxy-3β-[3-(2'H-1,2,3-triazol-2'-yl)-1-propynyl]-5β-pregnan-20-one

A solution of 2-(2-propynyl)-2H-1,2,3-triazole (prepared by the reactionof triazole with propargyl bromide) (35 mg, 0.33 mmol) in dry THF (10mL) was treated with n-BuLi (2.5M in THF, 0.33 mmol, 0.15 mL) at -70° C.After stirring the mixture at -75° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (60 mg, 0.16mmol) in THF (10 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the mixture was quenched withNH₄ Cl solution (1 mL). The solvent was removed and the residue was thendissolved in acetone (25 mL). After adding 2N HCl (2 mL) the solutionwas stirred at rt for 30 min. Sat. NaHCO₃ soln. was added to neutralizethe acid. The solvents were removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product. This crude product was then dissolved in a small amountof CH₂ Cl₂ and poured on a column of silica gel. Elution withtoluene:acetone mixture (85:15) gave pregnan-3,20-dione (20 mg) as afirst fraction. Further elution with the same solvent yielded3α-hydroxy-3β-[3-(2'H-1,2,3-triazol-2'-yl)-1-propynyl]-5β-pregnan-20-one(20 mg) as a colorless solid; mp 139-140° C.; TLC R_(f) (hexane:acetone4:1)=0.17.

Example 32 3α-Hydroxy-3β-(2'-thienyl)ethynyl-5β-pregnan-20-one

A solution of 4-iodothiophene (63 mg, 0.3 mmol),3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (103 mg, 0.3 mmol) in drydegassed triethylamine (1 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)palladium(II) dichloride (5 mg) and CuI (5 mg)were added and the mixture was stirred at this temp. for 45 min. CH₂ Cl₂(5 mL) was added and the mixture was stirred at 23° C. for 1 hr. The TLCshowed 100% conversion of the starting material, hence, the solvent wasremoved, and the residue was purified by chromatography on silica gel.Elution with hexane:acetone (4:1) gave3α-hydroxy-3β-(2'-thienyl)ethynyl-5β-pregnan-20-one (50 mg) as acolorless solid; mp 205-206° C., TLC R_(f) (hexane:acetone 4:1)=0.35.

An analogus method was used to prepare3α-hydroxy-3β-(5'-acetyl-2'-thienyl)ethynyl-5β-pregnan-20-one; mp226-228° C., TLC R_(f) (hexane:acetone 4:1)=0.14.

Example 33 3α-Hydroxy-3β-(3'-phenyl-1'-propynyl)-5β-pregnan-20-one

A solution of 3-phenyl-1-propyne (0.25 mL, 2 mmol) in dry THF (17 mL)was treated with n-BuLi (2.5M in THF, 2 mmol, 0.8 mL) at -70° C. Afterstirring the mixture at -75° C. for 10 min., a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (206 mg, 0.6mmol) in THF (10 mL) was added and the mixture was stirred at -78° C.for 20 min. The cooling bath was removed and the mixture was quenchedwith NH₄ Cl solution (5 mL). The solvent was removed and the residue wasthen dissolved in acetone (15 mL). After adding 2N HCl (4 mL) thesolution was stirred at rt for 20 min. Sat. NaHCO₃ soln. was added toneutralize the acid. The solvents were removed and the residue wasextracted with EtOAc. The organic layer was washed with water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (460 mg). This crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with toluene:acetone mixture (85:15) gave theunreacted phenylpropyne as a first fraction. Further elution with thesame solvent yielded3α-hydroxy-3β-(3'-phenyl-1'-propynyl)-5β-pregnan-20-one (175 mg) as acolorless solid; mp 124-132° C.; TLC R_(f) (hexane:acetone 7:3)=0.46.

Example 34 3α-Hydroxy-3β-(3'-phenylpropynyl)-5β-pregnan-20-one

A solution of the above phenylpropynyl derivative (50 mg) in EtOAc (10mL) was hydrogenated over Pd/C (10 mg, 5%) under 2 atm. of H₂ for 45min. The mixture was then filtered through a small pad of Celite, andconcentrated to yield the title compound as a colorless solid (40 mg);mp 41-46° C.; R_(f) (hexane:acetone 7:3)=0.48.

Example 353α-Hydroxy-3β-[3-(1'H-pyrazol-1'-yl)-1-propynyl]-5β-pregnan-20-one

A solution of 1-(2-propynyl)-1H-pyrazole (prepared by the reaction ofpyrazole with propargyl bromide (160 mg, 1.5 mmol) in dry THF (15 mL)was treated with n-BuLi (2.5M in THF, 1.5 mmol, 0.6 mL) at -70° C. Afterstirring the mixture at -75° C. for 0.5 hr, a solution of5β-pregnan-3,20-dione, cyclic 20-(1,2-ethanediyl acetal) (180 mg, 0.5mmol) in THF (15 mL) was added and the mixture was stirred at -78° C.for 1 hr. The cooling bath was removed and the mixture was quenched withNH₄ Cl solution (1 mL). The solvent was removed and the residue was thendissolved in acetone (25 mL). After adding 2N HCl (2 mL) the solutionwas stirred at rt for 30 min. Sat. NaHCO₃ soln. was added to neutralizethe acid. The solvents were removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product. This crude product was then dissolved in a small amountof CH₂ Cl₂ and poured on a column of silica gel. Elution wastoluene:acetone mixture (9:1) gave3α-hydroxy-3β-[3-(1'H-pyrazol-1'-yl)-1-propynyl]-5β-pregnan-20-one (80mg) as a colorless solid; mp 113-115° C.; TLC R_(f) (toluene:acetone9:1)=0.19.

Example 36 3β-(3'-Acetylphenylethynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of 3-iodoacetophenone (74 mg, 0.3 mmol),3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (103 mg, 0.3 mmol) in drydegassed triethylamine (1 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)palladium(II) dichloride (5 mg) and CuI (5 mg)were added and the mixture was stirred at this temp. for 45 min. CH₂ Cl₂(5 mL) was added and the mixture was stirred at 23° C. for 1.5 hr. TheTLC showed 100% conversion of the starting material, hence, the solventwas removed and the residue was purified by chromatography on silicagel. Elution with hexane:acetone (85:15) gave3β-(3'-acetylphenylethynyl)-3α-hydroxy-5β-pregnan-20-one (30 mg) as acolorless solid; mp ° C., TLC R_(f) (hexane:acetone 4:1)=0.

Example 37 3β-(3'-Acetoxy-3'-propynyl)-3α-hydroxy-5β-pregnan-20-one

A solution of pyridine (280 mg) in CH₂ Cl₂ (2 mL) was treated withacetyl chloride (280 mg) at 0-5° C. A solution of3β-(3'-hydroxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one (130 mg) in CH₂Cl₂ (3 mL) was added. The stirring was continued at 0° C. for 30 min.The TLC showed 100% conversion, hence, the mixture was poured intoice-2N HCl (20 g, 3 mL). The organics were extracted with EtOAc. Theorganic layer was washed with 0.2N HCl, water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product (150 mg). This crude product was then dissolved in a smallamount of CH₂ Cl₂ and poured on a column of silica gel. Elution withtoluene:acetone mixture (4:1) gave3β-(3'-acetoxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one (110 mg); mp132-150° C.; TLC R_(f) (hexane:acetone 70:30)=0.37.

Example 383α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-pregnan-20-onea. 21-Bromo-3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-5β-pregnan-20-one

A solution of 3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-5β-pregnan-20-one (386mg, 1 mmol) in MeOH (20 mL) was treated with two drops of acetylchloride, followed by bromine (1.2 mmol). The mixture was stirred at rtfor 2.5 hr and was poured into ice-water. The separated solid wascollected by filtration, washed with water, dried (410 mg). Thissemi-dried solid was then dissolved in EtOAc and dried over anhyd.MgSO₄. Filtration and removal of the solvent gave the crude bromoderivative, and it was used as such for the next step.

b.3α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-1-imidazolyl)-5β-pregnan-20-one

A suspension of NaH (138 mg, 95%, 5.46 mmol) in THF (10 mL) was treatedwith a solution of imidazole (345 mg, 5.1 mmol) in THF (10 mL) at rt.After stirring the mixture for 30 min a solution of the crude bromoderivative (95 mg, 0.2 mmol) in THF (10 mL) was added. The stirring wascontinued at rt for 1 hr. Sat. NH₄ Cl soln. was added and the solventwas removed. The residue was extracted with EtOAc. The organic layer waswashed with water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to yield the crude product (100mg). This crude product was then dissolved in a small amount of CH₂ Cl₂and poured on a column of silica gel. Elution with CH₂ Cl₂ :MeOH:NEt₃(95:4.5:0.5) mixture gave3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-pregnan-20-one(40 mg) as a colorless solid; mp 117-119° C.; TLC R_(f) (CH₂ Cl₂:MeOH:NEt₃ 95:4.5:0.5) 0.21.

Similarly prepared were3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1,2,4-triazol-1-yl)-5.beta.-pregnan-20-one;mp 208-210° C.; TLC R_(f) (CH₂ Cl₂ :MeOH:NEt₃ 95:4.5:0.5) 0.24;3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(tetrazol-1--yl)-5β-pregnan-20-one;mp 110-112° C.; TLC R_(f) (CH₂ Cl₂ :MeOH:NEt₃ 96:3.5:0.5) 0.11;3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1,2,3-triazol-1-yl)-5.beta.-pregnan-20-one;mp 101-104° C.; TLC R_(f) (CH₂ Cl₂ :MeOH:NEt₃ 95:4.5:0.5) 0.2.

Example 393α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-norpregnan-20-onea. 21-Bromo-3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-5β-19-norpregnan-20-one

A solution of3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-norpregnan-20-one(710 mg, 1.9 mmol) in MeOH (60 mL) was heated to 33° C. and was treatedwith two drops of acetyl chloride, followed by bromine (2.28 mmol,(0.116 mL). The mixture was stirred at rt for 1.5 hr and was poured intoice-water. The separated solid was collected by filtration, washed withwater, dried. This semi-dried solid was then dissolved in EtOAc anddried over anhyd. MgSO₄. Filtration and removal of the solvent gave thecrude bromo derivative (870 mg), and it was used for the next step.

b.3α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-norpregnan-20-one

A suspension of NaH (138 mg, 95%, 5.46 mmol) in THF (10 mL) was treatedwith a solution of imidazole (345 mg, 5.1 mmol) in THF (10 mL) at rt.After stirring the mixture for 30 min a solution of the crude bromoderivative (90 mg, 0.2 mmol) in THF (10 mL) was added. The stirring wascontinued at rt for 1 hr. Sat. NH₄ Cl soln. was added and the solventwas removed. The residue was extracted with EtOAc. The organic layer waswashed with water, and brine. After drying over anhyd. MgSO₄ thesolution was filtered and evaporated to yield the crude product (100mg). This crude product was then dissolved in a small amount of CH₂ Cl₂and poured on a column of silica gel. Elution with CH₂ Cl₂ :MeOH:NEt₃(95:4.5:0.5) mixture gave3α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1-imidazolyl)-5β-norpregnan-20-one(25 mg) as a colorless solid; mp 118-127° C.; TLC R_(f) CH₂ Cl₂:MeOH:NEt₃ 95:4.5:0.5) 0.28.

Example 403α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1,2,3-triazol-2-yl)-5.beta.-19-norpregnan-20-oneand3α-Hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1,2,3-triazol-1-yl)-5.beta.-19-norpregnan-20-one

A suspension of NaH (11 mg, 95%, 0.44 mmol) in THF (10 mL) was treatedwith a solution of 1,2,3-triazole (30 mg, 0.44 mmol) in THF (10 mL) atrt. After stirring the mixture for 30 min a solution of the crude21-bromo-3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-5β-pregnan-20-one (100 mg,0.22 mmol) in THF (10 mL) was added. The stirring was continued at rtfor 1 hr. Sat. NH₄ Cl soln. was added and the solvent was removed. Theresidue was extracted with EtOAc. The organic layer was washed withwater, and brine. After drying over anhyd. MgSO₄ the solution wasfiltered and evaporated to yield the crude product (100 mg). This crudeproduct was then dissolved in a small amount of CH₂ Cl₂ and poured on acolumn of silica gel. Elution with CH₂ Cl₂ :acetone (4:1) mixture gave3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(2H-1,2,3-triazol-2-yl)-5β-19-nonpregnan-20-one(15 mg) as a first fraction; mp 158-160° C.; TLC R_(f) (CH₂ Cl₂ :acetone4:1) 0.36. Further elution with the same solvent mixture yielded3α-hydroxy-3β-(4-hydroxybutyn-1-yl)-21-(1H-1,2,3-triazol-2-yl)-5β-19-nonpregnan-20-one(15 mg); mp 188-190° C.; TLC R_(f) (CH₂ Cl₂ :acetone 4:1) 0.2.

Example 41 3α-Hydroxy-2β-morpholinyl-21-[1'-(1', 2',4'-triazolyl)]-5α-pregnan-20-one

To a solution of 1,2,4-triazole (108 mg, 1.57 mmol) in dry THF (2.5 ml)was added sodium hydride (36 mg, 1.50 mmol). The mixture was stirred at25° C. under argon for 0.5 hour. Then3α-hydroxy-2β-morpholinyl-21-bromo-5α-pregnan-20-one (130 mg, 0.27 mmol)was added and the mixture was further stirred at 25° C. under argon for2.5 hours. Water (20 ml) was added slowly to the reaction mixture. Theproduct was extracted with ethyl acetate (3×25 ml). The combinedextracts were washed with brine (20 ml) and water (3×20 ml). The organicsolution obtained was dried over sodium sulfate and the solvent wasremoved in vacuo to give the crude product (130 mg). The pure product(90 mg, 71%) was obtained by flash chromatography (30 g of silica geland 300 ml of mixed solvent of CH₂ Cl₂ :MeOH:Et₃ N=95:4.5:0.5, R_(f)=0.14).

Example 42 3α-Hydroxy-21-(1'-uracil)-5α-pregnan-20-one

To a suspension of uracil (112 mg, 1 mmol) and K₂ CO₃ (138 mg, 1 mmol)in DMF (1.5 mL) was added 3α-hydroxy-21-bromo-5α-pregnan-20-one (400 mg,1 mmol) and the mixture obtained was stirred at 25° C. for 65 h. It wasthen poured into a separatory funnel containing water (60 ml) and ethylacetate (100 mL). The water was removed after shaking and the whitesolid in the organic layer was obtained by filtration as the product (87mg, 20%). m.p.262-265° C. (decomp).

Example 43 Sodium S-(3α-hydroxy-5α-pregnan-20-on-21-yl) thiosulfate

To a solution of 21-bromo-3α-hydroxy-5α-pregnan-20-one (500 mg, 1.26mmol) dissolved in 50 mL of ethanol was added dropwise a solution ofsodium thiosulfate (199 mg, 1.26 mmol) in 10 mL of water. The reactionwas allowed to stir at rt until TLC (1:1 acetone/dichloromethane)indicated complete consumption of the starting bromide. Concentration ofthe reaction in vacuo gave the desired thiosulfate contaminated withsodium bromide. Flash column chromatography (silica gel eluted with agradient from 1:1 to 3:1 acetone/dichloromethane) afforded 430 mg (75%)of the title compound as a white solid.

Similarly prepared were sodiumS-(3α-hydroxy-3β-methyl-5α-pregnan-20-on-21-yl) thiosulfate, purified byflash chromatography as above, sodiumS-(3α-hydroxy-3β-methoxymethyl-5α-pregnan-20-on-21-yl) thiosulfate,purified by recrystallization from 50:1 methanol/water, sodiumS-(3α-hydroxy-5β-pregnan-20-on-21-yl) thiosulfate, purified by flashchromatography with silica gel and 3:1 acetone/ethanol, sodiumS-[3α-hydroxy-3β-(4'-hydroxybutynyl)-5β-pregnan-20-on-21-yl]thiosulfate, purified by trituration with hot acetone, andsodiumS-(3α-hydroxy-3β-trifluoromethyl-5β-19-nonpregnan-20-on-21-yl)thiosulfate, purified by trituration with hot acetone/chloroform.

Example 44 3α-Hydroxy-3β-(E)-(2-phenylethenyl)-5α-pregnan-20-one Benzylphenyl sulfoxide

To a solution of benzyl phenyl sulfide (Aldrich; 1.068 g, 5.33 mmol) in25 mL of CH₂ Cl₂ at -78° C. was slowly added a solution ofm-chloroperbenzoic acid (Aldrich, 50-60%; 760 mg, 2.64 mmol if 60%) in10 mL of CH₂ Cl₂. After warming to room temperature and stirringovernight, the solution was added to 20 mL of a saturated NaHCO₃solution. The aqueous layer was separated and extracted with CH₂ Cl₂(2×10 mL). The pooled organic layers were then dried (MgSO₄) andconcentrated. The residue was subjected to flash column chromatography(silica gel, 10% acetone/hexane and 15% acetone/hexane) affording thesulfoxide (632 mg, 55%) as a white solid, mp 123-126° C.

20,20-ethylenedioxy-3α-hydroxy-3β-[[2-(phenylsulfinyl)-2-phenyl]ethyl]-5α-pregnane

A solution of diisopropylamine (Aldrich, freshly distilled from CaH₂ ;0.5 mL, 361 mg, 3.57 mmol) in 2 mL of dry THF was cooled to -10° C. andtreated with a 1.6 M solution of n-BuLi in hexanes (Aldrich; 1.0 mL, 1.6mmol) added dropwise via syringe. After 10 m, the reaction was cooled to-75° C. and a solution of benzyl sulfoxide (347 mg, 1.60 mmol) in 5 mLof dry THF was added dropwise via syringe over 30 m. To the resultingdeep yellow solution was added 297 mg (0.79 mmol) of solid20,20-ethylenedioxy-3(R)-5α-pregnan-3-spiro-2'-oxirane. The reaction wasallowed to warm to rt and then warmed to 50° C. After 5 h, the reactionwas allowed to cool to rt and added to 30 mL of ice-cold water. Theresulting mixture was extracted with EtOAc (3×20 mL). The combined EtOAclayers were back extracted with a sat. NaCl solution, dried (Na₂ SO₄)and concentrated. The residue was purified by flash chromatography(silica gel, gradient from 100% CH₂ Cl₂ to 20% acetone/CH₂ Cl₂.)affording the sulfoxide (405 mg, 86%) as a mixture of two diastereomers(based on two benzylic protons in ¹ H NMR).

3α-Hydroxy-3β-[[2-phenylsulfinyl)-2-phenyl]ethyl]-5α-pregnan-20-one

A solution of20,20-ethylenedioxy-3α-hydroxy-3β-[[2-phenylsulfinyl)-2-phenyl]ethyl]-5α-pregnane(1.30 g, 2.21 mmol) in 15 mL of THF was cooled in an ice/water bath andan aqueous 1N HCl solution (3 mL) was added followed by 2 mL of acetone.After stirring at rt for 70 min, the reaction was recooled to 0° C. andadded to an EtOAc/water mixture containing 6 mL of a sat. NaHCO₃solution. The aqueous layer was extracted twice with EtOAc and thecombined organic layers were extracted with a sat. NaCl solution, dried(Na₂ SO₄) and concentrated. The residue was carried on to the next stepwithout purification.

3α-Hydroxy-3β-(E)-(2-phenylethenyl)-5α-pregnan-20-one

A suspension of3α-hydroxy-3β-[[2-phenylsulfinyl)-2-phenyl]ethyl]-5α-pregnan-20-one (963mg, 1.76 mmol) in 6 mL of p-cymene containing 0.95 mL of 2,4,6-collidinewas heated at 135° C. for 1 hr. After standing overnight at 0° C., theproduct had precipitated and was isolated by filtration. The crudeproduct was washed with cold p-cymene (3×5 mL) and hexane (a total of120 mL) and afforded 445 mg of the title compound as a white solid, mp209-213° C.

Example 45 3α-Hydroxy-2β-trimethylsilylethynyl-5α-pregnan-20-one

A solution of trimethylsilylacetylene (0.5 mL, 0.347 g, 3.54 mmol) in 4mL of dry THF was cooled to -78° C. and treated with a 2.5 M solution ofn-BuLi in hexanes. Neat BF₃ -Et₂ O (0.3 mL, 0.346 g, 2.44 mmol) wasadded via syringe. After stirring at -78° C. for 5 m, a solution of20,20-ethylenedioxy-5α-pregnan-2α,3α-epoxide (557 mg, 1.54 mmol) in 3 mLof dry THF was added over 12 m. After an additional 2.5 h, the reactionwas added to a sat. NH₄ Cl solution. The resulting mixture was extractedwith EtOAc (3×25 mL). The combined organic layers were washed with abrine solution, dried (Na₂ SO₄) and concentrated under reduced pressure.The crude reaction mixture was dissolved in 10 mL of acetone, cooled inan ice/water bath and treated with a 1N HCl solution (1 mL). After 1 hat rt, the reaction was added to an ether/water mixture containing 1 mLof a sat. NaHCO₃ solution. The aqueous layer was washed twice with etherand the pooled ether layers were washed with a sat. NaCl solution, dried(Na₂ SO₄) and concentrated. Flash column chromatography (silica gel,12.5% acetone/hexane) afforded 249 mg of the title compound as a whitesolid, mp 164-167° C.

The procedure above was used for the preparation of3α-hydroxy-2β-(3'-methoxy-1'-propynyl)-5α-pregnan-20-one.

The hydrolysis of the trimethylsilyl compound with K₂ CO₃ /MeOH gave3α-hydroxy-2β-ethynyl-5α-pregnan-20-one as a white solid, m.p. 179-189°C. (decomp.).

Example 46 3α,21-Dihydroxy-3β-ethynyl-5β-pregnan-20-one a.21-Bromo-3β-ethynyl-3α-hydroxy-5β-pregnan-20-one

A solution of 3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (3 g, 8.77 mmol)in MeOH (110 mL) was treated with two drops of HBr (48%), followed bybromine (0.5 mL, 10.8 mmol). The mixture was stirred at room temperaturefor 1 hr and was poured into ice-water. The separated solid wascollected by filtration, washed with water, and dried (3.2 g). Thissemi-dried solid was then dissolved in EtOAc and dried over anhyd.MgSO₄. Filtration and removal of the solvent gave the crude bromoderivative. This crude product was then dissolved in a small amount ofCH₂ Cl₂ and poured on a column of silica gel. Elution with hexane:EtOAcmixture (4:1) gave 21-bromo-3β-ethynyl-3α-hydroxy-5β-pregnan-20-one (3.2g).

b. 3α,21-Dihydroxy-3β-ethynyl-5β-pregnan-20-one

A solution of the above bromo derivative (3.2 g) in acetone (100 mL) wastreated with trifluoroacetic acid (5.8 mL, 76 mmol) and triethylamine(8.5 mL). The mixture was refluxed for 30 min. and then trifluoroaceticacid sodium salt (10 g) was added in portions over a period of 10 hr.After cooling to room temperature, a solution of sat. NaHCO₃ was added.The solvent was removed and the residue was extracted with EtOAc. Theorganic layer was washed with water, and brine. After drying over anhyd.MgSO₄ the solution was filtered and evaporated to yield the crudeproduct. This crude product was then dissolved in a small amount of CH₂Cl₂ and poured on a column of silica gel. Elution with hexane:EtOAcmixture (3:2) gave 3α,21-dihydroxy-3β-ethynyl-5β-pregnan-20-one (1.6 g).mp 156-157° C.; TLC R_(f) (hexane:acetone 3:1)=0.2.

Example 47 3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one

A solution of 4-iodoacetophenone (1.22 g, 4.44 mmol),3α,21-dihydroxy-3β-ethynyl-5β-pregnan-20-one (1.59 g, 4.44 mmol) in drydegassed triethylamine (7 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)palladium chloride (15 mg) and CuI (5 mg) wasadded and the mixture was stirred at this temp. for 45 min. CH₂ Cl₂ (30mL) was added and the mixture was stirred at 23° C. for 1.5 hr. TLCshowed 100% conversion of the starting material, hence, the solvent wasremoved and the residue was purified by chromatography on silica gel.Elution with hexane:acetone (4:1) gave3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one (1.3 g) asa colorless solid; mp 181-183° C., TLC R_(f) (hexane:acetone 3:2)=0.14.

Example 48 3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt a.3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate

A solution of3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one (1.3 g,6.76 mmol) in pyridine (8 mL) was treated with succinic anhydride (680mg, 2.5 mmol) and 4-(N,N-dimethyl)aminopyridine (25 mg). The mixture washeated to 70-75° C. for 2.5 hr. TLC showed 100% conversion. Pyridine wasremoved and the residue was extracted with EtOAc. The organic layer waswashed with 0.1N HCl, water, and brine. After drying over anhyd. MgSO₄,the solution was filtered and evaporated to yield the crude product.This crude product was then dissolved in a small amount of CH₂ Cl₂ andpoured on a column of silica gel. Elution with hexane:acetone mixture(7:3) gave3β-(4'-acetylphenyl-ethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate (1.4 g).

b. 3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt

A mixture of the above hemisuccinate (1.5 g, 2.6 mmol), NaHCO₃ (220 mg,2.6 mmol), water (10 mL), and CH₂ Cl₂ (16 mL) was stirred at roomtemperature for 1 hr. The solvent was removed and the residue wasfreeze-dried to yield the sodium salt as a colorless solid (1.4 g).

Example 49 3α,21-Dihydroxy-3β-ethynyl-5α-pregnan-20-one a.21-Bromo-3β-ethynyl-3α-hydroxy-5α-pregnan-20-one

A solution of 3β-ethynyl-3α-hydroxy-5α-pregnan-20-one (2.3 g, 6.72 mmol)in MeOH (80 mL) was treated with two drops of HBr (48%), followed bybromine (0.4 mL, 7.73 mmol). The mixture was stirred at room temperaturefor 1 hr and was poured into ice-water. The separated solid wascollected by filtration, washed with water, and dried (2.5 g). Thissemi-dried solid was then dissolved in EtOAc and dried over anhyd.MgSO₄. Filtration and removal of the solvent gave the crude bromoderivative. This crude product was then dissolved in a small amount ofCH₂ Cl₂ and poured on a column of silica gel. Elution with hexane:EtOAcmixture (85:15) gave 21-Bromo-3β-ethynyl-3α-hydroxy-5α-pregnan-20-one(2.1 g).

b. 3α,21-Dihydroxy-3β-ethynyl-5α-pregnan-20-one

A solution of the above bromo derivative (2.1 g, 5 mmol) in acetone (40mL) was treated with trifluoroacetic acid (3.8 mL, 50 mmol) andtriethylamine (5.5 mL). The mixture was refluxed for 30 min. and thentrifluoroacetic acid sodium salt (10 g) was added in parts over a periodof 10 hr. After cooling to room temperature, a solution of sat. NaHCO₃was added. The solvent was removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product (1.6 g). This crude product was then dissolved in a smallamount of CH₂ Cl₂ and poured on a column of silica gel. Elution withhexane:EtOAc mixture (7.3) gave3α,21-dihydroxy-3β-ethynyl-5α-pregnan-20-one (1.5 g), mp 214-218° C.;TLC R_(f) (hexane:acetone 7:3)=0.33.

Example 50 3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one

A solution of 4-iodoacetophenone (962 mg, 4 mmol),3α,21-dihydroxy-3β-ethynyl-5α-pregnan-20-one (1.2 g, 4 mmol) in drydegassed triethylamine (7 mL) was stirred under argon at 23° C.Bis(triphenyl-phosphine)palladium chloride (15 mg) and CuI (5 mg) wereadded and the mixture was stirred at this temp. for 45 min. CH₂ Cl₂ (25mL) was added and the mixture was stirred at 23° C. for 1.5 hr. TLCshowed 100% conversion of the starting material, hence, the solvent wasremoved and the residue was purified by chromatography on silica gel.Elution with hexane:acetone (7:3) gave3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one (750 mg)as a colorless solid; mp 222-225° C., TLC R_(f) (hexane:acetone4:1)=0.13.

Example 51 3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt a.3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate

A solution of3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one (276 mg,1.4 mmol) in pyridine (4 mL) was treated with succinic anhydride (680mg, 2.7 mmol) and 4-(N,N-dimethyl)aminopyridine (20 mg). The mixture washeated to 70-75° C. for 2.5 hr. TLC showed 100% conversion. Pyridine wasremoved in vacuo and the residue was extracted with EtOAc. The organiclayer was washed with 0.1N HCl, water, and brine. After drying overanhyd. MgSO₄ the solution was filtered and evaporated to yield the crudeproduct. This crude product was then dissolved in a small amount of CH₂Cl₂ and poured on a column of silica gel. Elution with hexane:acetonemixture (7:3) gave3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate (400 mg).

b. 3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemisuccinate sodium salt

A mixture of the above hemisuccinate (400 mg, 0.7 mmol), NaHCO₃ (60 mg,0.7 mmol), water (3 mL), and CH₂ Cl₂ (5 mL) was stirred at roomtemperature for 1 hr. The solvent was removed and the residue wasfreeze-dried to yield the sodium salt as a colorless solid (390 mg).

Example 52 3α-Hydroxy-3β-(3-pyridyl)ethynyl-5β-pregnan-20-one

A solution of 3-bromopyridine (70 mg, 0.44 mmol),3β-ethynyl-3α-hydroxy-5α-pregnan-20-one (150 mg, 0.44 mmol) in drydegassed diethylamine (1 mL) was stirred under argon at 23° C.Bis(triphenylphosphine)palladium chloride (10 mg) and CuI (5 mg) wereadded and the mixture was stirred at this temp. for 45 min. CH₂ Cl₂ (4mL) was added and the mixture was stirred at 23° C. for 1.5 hr. TLCshowed 100% conversion of the starting material, hence, the solvent wasremoved and the residue was purified by chromatography on silica gel.Elution with hexane:acetone (3:1) gave3α-hydroxy-3β-(3-pyridyl)ethynyl-5β-pregnan-20-one (30 mg) as acolorless solid; mp 230-35° C., TLC R_(f) (hexane:acetone 7:3)=0.24.

Example 5321-Bromo-3α-Hydroxy-3β-(3-hydroxypropyn-1-yl)-5β-pregnan-20-one

A solution of 3α-hydroxy-3β-(3-hydroxypropyn-1-yl)-5β-pregnan-20-one(483 mg, 1.3 mmol) in MeOH (20 mL) was heated to 33° C. and was treatedwith two drops of HBr (48%), followed by bromine (1.43 mmol, 0.73 mL).The mixture was stirred at 37° C. for 1 hr and was poured intoice-water. The separated solid was collected by filtration, washed withwater, and dried. This semi-dried solid was then dissolved in EtOAc anddried over anhyd. MgSO₄. Filtration and removal of the solvent gave thecrude 21-bromo-3α-hydroxy-3β-(3-hydroxypropyn-1-yl)-5β-pregnan-20-one(322 mg).

EXAMPLE 543α-Hydroxy-3β-(3-hydroxypropyn-1-yl)-21-(1,2,3-triazol-2-yl)-5.beta.-pregnan-20-oneand3α-hydroxy-3β-(3-hydroxypropyn-1-yl)-21-(1,2,3-triazol-1yl)-5.beta.-pregnan-20-one

A suspension of NaH (30 mg, 95%, 1.2 mmol) in THF (10 mL) was treatedwith a solution of 1,2,3-triazole (69 mg, 1mmol) in THF (10 mL) at roomtemperature. After stirring the mixture for 30 min. a solution of thecrude bromo derivative of Example 53 (162 mg, 0.37 mmol) in THF (10 mL)was added. The stirring was continued at room temperature for 1.5 hr.Sat. NH₄ Cl soln. was added and the solvent was removed. The residue wasextracted with EtOAc. The organic layer was washed with water, andbrine. After drying over anhyd. MgSO₄ the solution was filtered andevaporated to yield the crude product (250 mg). This crude product wasthen dissolved in a small amount of CH₂ Cl₂ and poured on a column ofsilica gel. Elution with CH₂ Cl₂ :acetone (6:4) mixture gave3α-hydroxy-3β-(3-hydroxypropyn-1-yl)-21-(2H-1,2,3-triazol-2-yl)-5β-pregnan-20-one(40 mg) as a first fraction; mp 188-191° C.; TLC R_(f) (CH₂ Cl₂ :acetone6:4) 0.56. Further elution with the same solvent mixture yielded3α-hydroxy-3β-(3-hydroxypropyn-1-yl)-21-(1H-1,2,3-triazol-1-yl)-5β-pregnan-20-one(40 mg); mp 135-140° C.; TLC R_(f) (CH₂ Cl₂ :acetone 6:4) 0.34.

EXAMPLE 55 3β-(4'-Hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-11,20-dione

A solution of 3-butyn-1-ol (0.4 mL, 5.2 mmol) in dry THF (15 mL) wastreated with n-BuLi (4 mL, 2.5M in THF, 10 mmol) at -65° C. Afterstirring the mixture at -78° C. for 0.5 hr, a solution of5β-pregnan-3,11,20-trione, cyclic 20-(1,2-ethanediyl acetal) (800 mg,2.14 mmol) in THF (20 mL) was added and the mixture was stirred at -78°C. for 1 hr. The cooling bath was removed and the stirring was continuedat room temperature for 45 min. The mixture was then quenched with NH₄Cl solution (5 mL). The solvent was removed the residue was thendissolved in acetone (30 mL). After adding 2N HCl (7 mL) the solutionwas stirred at rt for 15 min. Sat. NaHCO₃ soln. was added to neutralizethe acid. The solvents were removed and the residue was extracted withEtOAc. The organic layer was washed with water, and brine. After dryingover anhyd. MgSO₄ the solution was filtered and evaporated to yield thecrude product. This crude product was then dissolved in a small amountof CH₂ Cl₂ and poured on a column of silica gel. Elution withtoluene:acetone mixture (3:1) gave the unreacted butynol as a firstfraction. Further elution with the same solvent mixture yielded3α-(4'-hydroxy-1'-butynyl)-3β-hydroxy-5β-pregnan-11,20-dione (100 mg),and then 3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-11,20-dione(400 mg) as a colorless solid; mp 158-162° C.; TLC R_(f)(toluene:acetone 3:1)=0.16.

It will be obvious to one skilled in the art that the above describedcompounds may be present as mixtures of diastereomers which may beseparated into individual diastereomers. Resolution of the diastereomersmay be conveniently accomplished by gas or liquid chromatography orisolation from natural sources. Unless otherwise specified herein,reference in the specification and claims to the compounds of theinvention, as discussed above, is intended to include all isomers,whether separated or mixtures thereof.

Where isomers are separated, the desired pharmacological activity willoften predominate in one of the diastereomers. As disclosed herein,these compounds display a high degree of sterospecificity. Inparticular, those compounds have the greatest affinity for the GABAreceptor complex are those with 3β-substituted-3α-hydroxypregnanesteroid skeletons.

The compounds of and used in the invention, that being the nontoxic,pharmaceutically acceptable, natural and synthetic, direct acting and"prodrug" forms of progesterone, deoxycorticosterone, and androstanemetabolites, have hitherto unknown activity in the brain at the GABA_(A)receptor complex. The present invention takes advantage of the discoveryof this previously unknown mechanism and activity.

The pharmaceutical compositions of this invention are prepared inconventional dosage unit forms by incorporating an active compound ofthe invention or a mixture of such compounds, with a nontoxicpharmaceutical carrier according to accepted procedures in a nontoxicamount sufficient to produce the desired pharmacodynamic activity in asubject, animal or human. Preferably, the composition contains theactive ingredient in an active, but nontoxic amount, selected from about1 mg to about 500 mg of active ingredient per dosage unit. This quantitydepends on the specific biological activity desired and the condition ofthe patient. Desirable objects of the compositions and methods of thisinvention are in the treatment of stress, anxiety, PMS, PND, andseizures such as those caused by epilepsy to ameliorate or prevent theattacks of anxiety, muscle tension, and depression common with patientssuffering from these central nervous system abnormalities. An additionaldesirable object of the composition and methods is to treat insomnia andproduce hypnotic activity. Another desirable object of the compounds anmethods is to induce anesthesia, particularly by intravenousadministration.

The pharmaceutical carrier employed may be, for example, either a solid,liquid, or time release (see e.g. Remington's Pharmaceutical Sciences,14th Edition, 1970). Representative solid carriers are lactose, terraalba, sucrose, talc, gelatin, agar, pectin, acacia, magnesium stearate,stearic acid, microcrystalline cellulose, polymer hydrogels and thelike. Typical liquid carriers are propylene glycol, glycofurol, aqueoussolutions of cyclodextrins, syrup, peanut oil, and olive oil and thelike emulsions. Similarly, the carrier or diluent may include anytime-delay material well known to the art, such as glycerol monostearateor glycerol distearate alone or with wax, microcapsules, microspheres,liposomes, and/or hydrogels.

A wide variety of pharmaceutical forms can be employed. Thus, when usinga solid carrier, the preparation can be plain milled micronized, in oil,tableted, placed in a hard gelatin or enteric-coated capsule inmicronized powder or pellet form, or in the form of a troche or lozenge.The compounds of and used in the invention may also be administered inthe form of suppositories for rectal administration. Compounds may bemixed in material such as cocoa butter and polyethylene glycols or othersuitable non-irritating material which is solid in rt but liquid at therectal temperature. When using a liquid carrier, the preparation can bein the form of a liquid, such as an ampule, or as an aqueous ornonaqueous liquid suspension. Liquid dosage forms also needpharmaceutically acceptable preservatives and the like. In addition,because of the low doses that will be required as based on the datadisclosed herein, parental administration, nasal spray, sublingual andbuccal administration, and timed release skin patches are also suitablepharmaceutical forms for topical administration.

The method of producing anxiolytic, anticonvulsant, mood altering (suchas anti-depressant) or hypnotic activity, in accordance with thisinvention, comprises administering to a subject in need of such activitya compound of the invention, usually prepared in a composition asdescribed above with a pharmaceutical carrier, in a nontoxic amountsufficient to produce said activity.

During menses, the levels of excreted metabolites vary approximatelyfourfold (Roscixzewska, et al.). Therefore, therapy for controllingsymptoms involves maintaining the patient at a higher level ofprogesterone metabolites than normal in the premenstrual state of PMSpatients. Plasma levels of active and major metabolites are monitoredduring pre-menses and post-menses of the patient. The amount of thecompounds of the invention administered, either singly or as mixturesthereof are thus calculated to reach a level which will exert GABA_(A)-receptor activity equal or higher than the level of progesteronemetabolites in the normal subject during the premenses state.

The route of administration may be any route that effectively transportsthe active compound to the GABA_(A) receptors that are to be stimulated.Administration may be carried out parenterally, enterally, rectally,intravaginally, intradermally, intramuscularly, sublingually, ornasally; the oral, intramuscular, and dermal routes are preferred. Forexample, one dose in a skin patch may supply the active ingredient tothe patient for a period of up to one week. However, the parenteralroute is preferred for status epilepticus.

Potency and Efficacy at the GR Site

The in vitro and in vivo experimental data show that thenaturally-occurring metabolites of progesterone/deoxycorticosterone andtheir derivatives interact with high affinity at a novel and specificrecognition site on the GR complex to facilitate the conductance ofchloride ions across neuronal membranes sensitive to GABA (Gee et al.,1987 Harrison et al., 1987).

To those skilled in the art, it is known that the modulation of [³⁵S]t-butylbicyclophosphorothionate ([³⁵ S]TBPS) binding is a measure ofthe potency and efficacy of drugs acting at the GR complex, which drugsmay be of potential therapeutic value in the treatment of stress,anxiety, and seizure disorders (Squires, R. F., et al., "[³⁵S]t-Butylbicyclophophorothionate binds with high affinity tobrain-specific sites coupled to a gamma aminobutyric acid-A and ionrecognition site," Mol, Pharmacol., 23:326, 1983; Lawrence, L. J., etal., "Benzodiazepine anticonvulsant action: gamma-aminobutyricacid-dependent modulation of the chloride ionophore," Biochem. Biophys.Res. Comm., 123:1130-1137, 1984; Wood, et al., "In vitrocharacterization of benzodiazepine receptor agonists, antagonists,inverse agonists and agonist/antagonists," Pharmacol, Exp. Ther.,231:572-576, 1984). We performed several experiments to determine thenature of the modulation of [³⁵ S]TBPS as affected by the compounds ofthe invention. We found that these compounds interact with a novel siteon the GR complex which does not overlap with the barbiturate, thebenzodiazepine or any other previously known sites. Furthermore, thesecompounds have high potency and efficacy at the GR complex, withstringent structural requirements for such activity. Preferred compoundswhich are useful in the present invention have an IC₅₀ of 2 μM or lessin the [³⁵ S]TBPS binding assay described herein below.

The procedure for performing this assay are fully discussed in: (1) Gee,et al., 1987; and (2) Gee, K. W., L. J. Lawrence, and H. I. Yamamura,"Modulation of the chloride ionophore by benzodiazepine receptorligands: influence of gamma-aminobutyric acid and ligand efficacy,"Molecular Pharmacology 30:218, 1986. These procedures were performed asfollows:

Brains from male Sprague-Dawley rats were removed immediately followingsacrifice and the cerebral cortices dissected over ice. A P₂ homogenatewas prepared as previously described (Gee, et al., 1986). Briefly, thecortices were gently homogenized in 0.32M sucrose followed bycentrifugation at 1000×g for 10 minutes. The supernatant was collectedand centrifuged at 9000×g for 20 minutes. The resultant P₂ pellet wassuspended as a 10% (original wet weight/volume) suspension in 50 mM Na/Kphosphate buffer (pH 7.4) 200 mM NaCl to form the homogenate.

One hundred microliter (ml) aliquots of the P₂ homogenate (0.5milligrams (mg) protein) were incubated with 2 nanomolar (nM) [³⁵ S]TBPS(70-110 curies/millimole;, New England Nuclear, Boston, Mass.) in thepresence of absence of the naturally occurring steroids or theirsynthetic derivatives to be tested. The tested compounds were dissolvedin dimethylsulfoxide (Baker Chem. Co., Phillipsbury, N.J.) and added tothe incubation mixture in 5 μL aliquots. The incubation mixture wasbrought to a final volume of 1 mL with buffer. Non-specific binding wasdefined as binding in the presence of 2 mM TBPS. The effect andspecificity of GABA (Sigma Chem. Co., St. Louis, Mo.) was evaluated byperforming all assays in the presence of GABA plus (+)bicuculline (SigmaChem. Co.). Incubations maintained at 25° C. for 90 minutes (steadystate conditions) were terminated by rapid filtration through glassfiber filters (No. 32, Schleicher and Schuell, Keene, N. H.).Filter-bound radioactivity was quantitated by liquid scintillationspectrophotometry. Kinetic data and compound/[³⁵ S]TBPS dose-responsecurves were analyzed by nonlinear regression using a computerizediterative procedure to obtain rate constants and IC₅₀ (concentration ofcompound at which half-maximal inhibition of basal [³⁵ S]TBPS bindingoccurs) values.

The experimental data obtained for this assay are also published in Gee,et al., 1987. The data discussed in this reference are shown as plots inFIGS. 1A and 1B. These plots show the effect of (+)bicuculline on thepregnane steroid alphaxalone (1A) and GABA (1B) modulation of 2 nM [³⁵S] TBPS binding to rat cerebral cortex. In these figures, (∘) representscontrol without bicuculline; () represents 0.5 μM bicuculline; (□)represents 1.0 μM bicuculline; (▪) represents 2.0 μM bicuculline; and(.increment.) represents 3.0 μM bicuculline. In this experiment, theeffect of (+)bicuculline on the ability of alphaxalone or GABA toinhibit the binding of [³⁵ S]TBPS was determined. Bicuculline is knownto be a competitive antagonist of GABA and a classical parallel shift inthe dose-response curves is observed in FIG. 1B. In contrast, thesteroid binding site identified by this work is distinct from theGABA/bicuculline site in FIG. 1A. The shift in dose-response curvesinduced by bicuculline when the inhibition of [³⁵ S]TBPS binding iscaused by alphaxalone is not parallel. This indicates that the GABA andsteroid sites do not overlap.

A second set of experiments were performed to demonstrate that steroids,barbiturates and benzodiazepines do not share common binding site on theGABA receptor. FIG. 2 shows the time course for the dissociation of [³⁵S] TBPS from rat cortical P₂ homogenates initiated by the addition of 2μM TBPS(▪), 1 μM 3α-hydroxy-5α-pregnan-20-one (□), 100 μM Napentobarbital () and 1 μM 3α-OH-5α-pregnan-20-one+100 μM Napentobarbital (∘). The assay was performed in accordance with theprocedures outlined above. These kinetic data show that the dissociationof [³⁵ S] TBPS binding initiated by saturating concentration of3α-hydroxy-5α-pregnan-20-one is potentiated by 100 μM Na pentobarbital.This effect is an indication that 3α-OH-5α-pregnan-20-one (steroid) andpentobarbital (barbiturate) bind to independent sites.

The third set of experiments examined the interactions between3α-hydroxy-5α-pregnan-20-one and Na pentobarbital in the potentiation of(³ H) flunitrazepam (FLU) binding. These experiments further support theclaim that steroids do not share common site of action withbenzodiazepines and barbiturates. In this series of experiments, theeffect of varying concentrations of 3α-hydroxy-5α-pregnan-20-one on (³H) FLU binding in the presence or absence of a maximally stimulatingconcentration of Na pentobarbital. Since Na pentobarbital has greatermaximum efficacy than that of 3α-hydroxy-5α-pregnan-20-one inpotentiating (³ H) FLU binding, 3α-hydroxy-5α-pregnan-20-one shouldultimately antagonize the effect of Na pentobarbital if the two interactcompetitively on the same site. This is not what was observed (FIG. 3).Thus, the data further support our conclusion that certain steroidsincluding the compounds of and used in the invention interact with anovel site distinct from the barbiturate or BZ regulatory site on the GRcomplex. Because of this independent site of action, it is anticipatedthat these steroid compounds will have therapeutic profiles differentfrom those of barbiturates and BZs.

Various compounds were screened to determine their potential asmodulators of [³⁵ S]TBPS binding in vitro. These assays were performedin accordance with the above discussed procedures. Based on theseassays, we have established the structure-activity requirements fortheir specific interaction at the GR complex and their rank orderpotency and efficacy. FIG. 4 provides [³⁵ S]TBPS inhibition of curves of3α-hydroxy-5α-pregnan-20-one (3α,5α-P),3α,21-dihydroxy-5α-pregnan-20-one (5α-THDOC) and R5020 (promogesterone)as experimental examples, while Table 1 provides IC₅₀ and maximuminhibition of numerous compounds, including examples of those claimed inthe application. IC₅₀ is defined as concentration of compounds toinhibit 50% of control [³⁵ S]TBPS binding. It is an indication of acompound's in vitro potency. Maximum inhibition is an indication of acompound's in vitro efficacy.

                                      TABLE 1                                     __________________________________________________________________________    COMPOUND                   IC.sub.50 (nM)                                                                     IMAX (%)                                      __________________________________________________________________________    3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20    -                           4    92                                                                            one                                            3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-on                                    e  5  93                                        3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-5α-19-norpregnan                                    -  6  90                                        20-one                                                                        3β-(4'-Carboxyphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-                                      7  79                                          one ethyl ester                                                               3β-(4'-Carboxyphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-                                      8  98                                           one ethyl ester                                                               3β-(4-Hydroxybutyn-1-yl)-3α-hydroxy-5β-pregnan-20-one                                       13 103                                          3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one                                      14 103                                        3β-(4'-Carboxyphenyl)ethynyl-3α-hydroxy-19-nor-5β-  15                                      94                                              pregnan-20-one ethyl ester                                                    3β-(4-Acetoxybutyn-1-yl)-3α-hydroxy-5β-pregnan-20-one                                       20  96                                          3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-2                                    0-  22  99                                      one                                                                           3β-(4-Hydroxybutyn-1-yl)-3α-hydroxy-5β-19-norpregnan-20-                                      22 102                                        one                                                                           3β-(3'-Methoxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one                                      27 105                                        3β-(4'-Dimethylaminophenyl)ethynyl-5β-pregnan-20-one  28  77                                       3β-[3-(2-propynyloxy)propyn-1-yl]-3.                                    alpha.-hydroxy-5β-pregnan-  28 105                                        20-one                                         3β-(4-Hydroxybutyn-1-yl)-3α-hydroxy-5α-pregnan-20-one                                      35  95                                          3α-Hydroxy-5α-pregnan-20-one  37  95                              3β-(4'-Biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one                                        43  83                                          3α-Hydroxy-3β-(4'-nitrophenyl)ethynyl-5β-pregnan-20-one                                      46 103                                         3α-Hydroxy-21-(2H-1,2,3,4-tetrazol-2-yl)-5β-pregnan-20-one                                       46  78                                          3α-Hydroxy-3β-(4'-methoxyphenyl)ethynyl-5β-pregnan-20-                                      47  89                                          one                                                                           3β-(4'-Trifluoromethylphenyl)ethynyl-3α-hydroxy-5β-  52                                      87                                             pregnan-20-one                                                                3β-(5-Acetylthien-2-yl)ethynyl-3α-hydroxy-5β-pregnan-20-                                      52  89                                        one                                                                           21-(1-Benzimidazolyl)-3α-hydroxy-5β-pregnan-20-one  53 100                                        3β-(4-Hydroxybutyn-1-yl)-3α-hy                                    droxy-21-(1-imidazolyl)-5β-  54  93                                       pregnan-20-one                                 3α-Hydroxy-21-(2H-1,2,3-triazol-2-yl)-5β-pregnan-20-one  56                                      79                                              3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-21-(1,2,3-triazol-2-                                       56  93                                          yl)-5β-19-norpregnan-20-one                                              3β-(4'-Chlorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one                                      58  89                                        3β-(5'-Hydroxypentyn-1'-yl)-3α-hydroxy-5β-pregnan-20-one                                      58 100                                        3α-Hydroxy-3β-(thien-2-yl)ethynyl-5β-pregnan-20-one  59                                     100                                             3β-(3'-Acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one                                      62 100                                        3α-Hydroxy-21-[1H-(4-methyl-5-carboxyl)imidazol-1-yl)]-5β-                                       62 100                                          pregnan-20-one                                                                3α-Hydroxy-3β-[3'-(2H-1,2,3-triazol-2-yl)-1-propynyl]-5β                                    -  66  98                                       pregnan-20-one                                                                3α-Hydroxy-21-(9H-1,2,3-purin-9-yl)-5β-pregnan-20-one  69                                        59                                              3α-Hydroxy-3β-[4'(R/S)-hydroxypentynyl]-5β-pregnan-20-                                      71 103                                          one                                                                           3α-Hydroxy-21-(imidazol-1-yl)-5α-pregnan-20-one  71  99                                          3α-Hydroxy-21-(imidazol-1-yl)-5.bet                                    a.-pregnan-20-one  73  57                       3β-(4'-Cyanophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one                                      73  92                                         3β,21-Dihydroxy-5α-pregnan-20-one(5α-THDOC)  76 100                                         3α-Hydroxy-3β-(pentafluorophen                                    yl)-ethynyl-5β-pregnan-20-  79  69                                        one                                            3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-21-(1,2,3-triazol-1-                                       79  96                                          yl)-5β-pregnan-20-one                                                    3β-Ethynyl-3α-hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-o                                    ne  80 103                                      3α-Hydroxy-3β-[3'-(1H-pyrazol-1-yl)-1'-propynyl]-5β-                                        81  98                                          pregnan-20-one                                                                3α-Hydroxy-3β-methyl-21-(2H-1,2,3-triazol-2-yl)-5α-                                        85  99                                          pregnan-20-one                                                                3β-[4'-(N,N-Diethylcarboxamidophenyl)ethynyl]-3α-hydroxy-                                        87  94                                          5β-pregnan-20-one                                                        3α-Hydroxy-3β-(4'-methylphenyl)ethynyl-5β-pregnan-20-one                                      88  84                                        3α-Hydroxy-3β-(6-oxo-1-heptynyl)-5β-pregnan-20-one  90                                      101                                             3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-21-(1,2,4-triazol-1-                                       93  96                                          yl)-5β-pregnan-20-one                                                    3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-21-(tetrazol-1-yl)-5.be                                    ta.-  93 101                                    pregnan-20-one                                                                3α-Hydroxy-3β-[4'(R/S)-hydroxypentynyl]-5β-pregnan-20-                                      94 104                                          one                                                                           3β-(5'-Acetoxypentyn-1'-yl)-3α-hydroxy-5β-pregnan-20-one                                      96  98                                        3α-Hydroxy-21-(1H-3,5-dimethylpyrazolyl)-5β-pregnan-20-  96                                      77                                              one                                                                           3α-Hydroxy-21-(1'-imidazolyl)-3β-methyl-5α-pregnan-20-o                                    ne  97  95                                      3α-Hydroxy-3β-(phenylethynyl)-5β-pregnan-20-one  98 101       3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-21-(1'-imidazolyl)-                                        98  98                                          5β-19-norpregnan-20-one                                                  3α-Hydroxy-21-(1'-pyrazolyl)-5α-pregnan-20-one 100  98                                           3β-(2'-Hydroxyphenyl)ethynyl-3.alpha                                    .-hydroxy-5β-pregnan-20- 101  83                                          one                                            3α-Hydroxy-3β-(3'-phenyl-1'-propynyl)-5β-pregnan-20-one                                     103  95                                         3β-Ethynyl-3α-Hydroxy-21-(1'-pyrazolyl)-5β-pregnan-20-on                                    e 106  99                                       Sodium S-[3α-hydroxy-3β-(4'-hydroxybutynyl)-5β-pregnan-                                     107  97                                         20-on-21-yl] thiosulfate                                                      3α-Hydroxy-3β-(2'-pyridyl)ethynyl-5β-pregnan-20-one 108                                      98                                             3β-(2.4-Difluorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-                                     109 102                                        one                                                                           3β-Benzyl-3α-hydroxy-5β-pregnan-20-one 109 102                21-(1'-Benzimidazolyl)-3α-hydroxy-3β-methyl-5α-pregnan-                                     109  95                                        20-one                                                                        3α-Hydroxy-21-(1'-pyrazolyl)-3β-methyl-5α-pregnan-20-on                                    e 115  98                                       3α-Hydroxy-3β-(5'-oxo-1-hexynyl)-5β-pregnan-20-one 118                                      101                                             3α-Hydroxy-21-(pyrazol-1-yl)-5β-pregnan-20-one 121  67                                            3β-(4'-Hydroxybutyn-1'-yl)-3α-                                    hydroxy-21-(1,2,3-triazol-1- 124  95                                           yl)-5β-19-norpregnan-20-one                                              3α-Hydroxy-3β-methyl-21-(1',2'                                    ,4'-triazolyl)-5α-pregnan-20- 125                                       105                                             one                                                                           3β-Ethynyl-3α-hydroxy-21-(1',2',4'-triazolyl)-5β-pregnan                                    -20- 127  98                                    one                                                                           3β-(4'-Cyanobutynyl)-3α-hydroxy-5β-pregnan-20-one 131                                       86                                              Sodium S-[3α-hydroxy-3β-(methoxymethyl)-5β-pregnan-20-                                      132 103                                         on-21-yl] thiosulfate                                                         Sodium S-(3α-hydroxy-5α-pregnan-20-on-21-yl)thiosulfate 133                                      90                                             3α-Hydroxy-3β-(2'-phenylethyl)-5β-pregnan-20-one 135                                        98                                              3α-Hydroxy-3β-methyl-21-(1',2',3'-triazol-1'-yl)-5α-pre                                    gnan- 136  99                                   20-one                                                                        3α-Hydroxy-3β-[3'-hydroxypropynyl]-5β-pregnan-20-one                                        137  93                                         3α-Hydroxy-3β-(3-pyridyl)ethynyl-5β-pregnan-20-one 138                                      100                                             3α-Hydroxy-3β-[3'(RS)-hydroxybutynyl]-5α-pregnan-20-one                                     144  99                                        3α-Hydroxy-3β-(4-pyridyl)ethynyl-5β-pregnan-20-one 149                                      103                                             3α-Hydroxy-21-(1',2',4'-triazol-1-yl)-5β-pregnan-20-one 151                                      60                                              Sodium S-(3α-hydroxy-3β-methyl-5α-pregnan-20-on-21-                                        151 101                                         yl)thiosulfate                                                                3β-(5'-Cyanopentynyl)-3α-hydroxy-5β-pregnan-20-one 158                                      100                                             3β-(4'-Acetoxyacetylphenyl)ethynyl-3α-hydroxy-5β-pregnan                                    - 171  91                                       20-one                                                                        3α-Hydroxy-3β-phenylpropyl-5β-pregnan-20-one 173  92                                         3α-Hydroxy-3β-[4'(R/S)-hydroxy                                    pentynyl]-5α-pregnan-20- 178 101                                         one                                            3α-Hydroxy-3β-[3'(RS)-hydroxybutynyl]-5β-pregnan-20-one                                     202 102                                         3β-(6-Hydroxyhexyn-1-yl)-3α-hydroxy-5β-pregnan-20-one                                       222  99                                         3α-Hydroxy-21-[1H-(2-methyl)imidizol-1-yl)-5β-pregnan-20-                                        222  95                                         one                                                                           3β-(3'-Acetoxypropyn-1'-yl)-3α-hydroxy-5β-pregnan-20-one                                     224 104                                        3α-hydroxy-21-(1'H-1,2,3,4-tetrazol-1'-yl)-5β-pregnan-20-                                        227  60                                         one                                                                           3α-Hydroxy-21-(2-formylimidazol-1-yl)-5β-pregnan-20-one 213                                      81                                              3α-Hydroxy-3β-(2'-methoxyphenyl)ethynyl-5β-pregnan-20-                                      238  99                                         one                                                                           3β-(4'-(hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-11,20-                                     268 102                                        dione                                                                         3β-[(3',4'-Dimethoxyphenyl)ethynyl]-3α-hydroxy-5β- 283                                      106                                             pregnan-20-one                                                                3α-Hydroxy-21-[1H-(4-nitro)imidazol-1-yl)]-5β-pregnan-20-                                        267  71                                         one                                                                           Sodium S-(3α-hydroxy-5β-pregnan-20-on-21-yl)thiosulfate 268                                      88                                              3β-(6'-Acetoxyhexyn-1'-yl)-3α-hydroxy-5β-pregnan-20-one                                     306  99                                         Sodium S-(3α-hydroxy-3β-trifluoromethyl-5β-19-norpregnan                                    - 325  98                                       20-on-21-yl) thiosulfate                                                      3α-Hydroxy-3β-phenyl-5β-pregnan-20-one 382  86                3β-(3'-Hydroxyphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-                                      407  99                                         one                                                                           3α-Hydroxy-3β-(3-hydroxypropyn-1-yl)-21-(1,2,3-triazol-2-                                        430 107                                         yl)-5β-pregnan-20-one                                                    3α-Hydroxy-21-(7'H-purin-7'-yl)-5β-pregnan-20-one 430  71                                         3α-Hydroxy-21-(1'-uracil)-5α-                                    pregnan-20-one 434  90                          3α-Hydroxy-3β-[3'-(pyrid-4-yloxy)-1'-propynyl]-5β-pregna                                    n- 465  94                                      20-one                                                                        3β-[2-(3',4'-Dimethoxyphenyl)ethyl]-3α-hydroxy-5β-pregna                                    n- 507  66                                      20-one                                                                        3α-Hydroxy-3β-(3'-hydroxyphenyl)-ethynyl-5β-pregnan-20-                                     619  98                                         one                                                                           3α-Hydroxy-3β-[3'-(1H-1,2,3-triazol-1-yl)-1'-propynyl]-5.beta                                    .- 655 102                                      pregnan-20-one                                                                3α-Hydroxy-3β-[3'-(1H-1,2,4-triazol-1-yl)-1'-propynyl]-5.beta                                    .- 843  99                                      pregnan-20-one                                                                3α-Hydroxy-3β-(3-hydroxypropyn-1-yl)-21-(1,2,3-triazol-1-                                        1089  101                                       yl)-5β-pregnan-20-one                                                    3β-[3'-(N,N-dimethylamino)-1'-propynyl]-3α-hydroxy-5β-                                      1420  100                                       pregnan-20-one                                                                3β-(4'-Acetoxyphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-on                                    e 1430  100                                     3β-(4-Hydroxyphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one                                     1550   88                                      3α-Hydroxy-2β-morpholinyl-21-(1H-1,2,4-tirazol-1-yl)-5α                                    - 1553   97                                     pregnan-20-one                                                                3α-Hydroxy-3β-(3'-oxopropynyl)-5β-pregnan-20-one 1720                                       76                                              3β-(4'-Carboxamidophenyl)ethynyl-3α-hydroxy-5β-pregnan-                                     2240   98                                       20-one                                                                        3β-(4'-Carboxamidobutynyl)-3α-hydroxy-5β-pregnan-20-one                                     2340  102                                       3α-Hydroxy-3β-(3'-oxobutynyl)-5β-pregnan-20-one 2690                                        107                                             3α-Hydroxy-3β-[3'-(N-imidazolyl)-1'-propynyl]-5β-pregnan                                    - 2720  107                                     20-one                                                                        5β-(5'-Carboxamidopentynyl)-3α-hydroxy-5β-pregnan-20-one                                     3090  102                                      Progesterone 5200  100                                                        3α-Hydroxy-3β-[3'-oxobutynyl]-5α-pregnan-20-one 6510                                       104                                             3β-(4'-Aminophenyl)ethynyl-3β-hydroxy-5β-pregnan-20-one                                      22500  103                                      3β-Hydroxy-5α-pregnan-20-one (Allopregnanolone) >10.sup.6                                        33                                              4-Pregnen-11β-21-diol-3,20-dione (Corticosterone) >10.sup.6  30                                         17β-Estradiol na.sup.a  0                 Cholesterol na  0                                                           __________________________________________________________________________     .sup.a na = not active                                                   

As can be seen from FIG. 4 and Table 1, 3α-hydroxy-5α-pregnan-20-one,3α,21-dihydroxy-5α-pregnan-20-one and compounds of and used in theinvention have low IC₅₀, which is the concentration necessary to achieve50% maximal inhibition of [³⁵ S]TBPS binding, while compounds such assex steroids (R5020, estradiol and progesterone), glucocorticoids(corticosterone) and cholesterol having a high IC₅₀ are essentiallyinactive. Thus, it is anticipated that hormonal steroids and cholesterolper se will not have any therapeutic value for the indications describedherein. In order to distinguish this unique class of steroids fromhormonal steroids, they are now termed neuroactive steroids. However,sex steroids such as progesterone can be metabolized in the body tosteroids similar to 3α-hydroxy-5α-pregnan-20-one. Thus, progesterone canbe considered as a prodrug. The TBPS data correlates with data on ³⁶ Clion uptake-potentiated by various 3α-hydroxylated steroids described inPurdy R. H., et al., "Synthesis, Metabolism, and PharmacologicalActivity of 3α-Hydroxy Steroids Which Potentiate GABA-Receptor-MediatedChloride Ion Uptake in Rat Cerebral Cortical Synaptoneurosomes," J. Med.Chem 33: 1572-1581 (1990), incorporated herein by reference and thesedata also correlate with electrophysiological data obtained by measuringsteroid's activity to potentiate GABA-induced current in oocytesinjected with human GABA receptors as shown in FIG. 5. This indicatesthat the TBPS assay is an approximate measurement of steroids ability toallosterically modulate Cl⁻ channel activity.

Compounds with Limited Efficacy

In as much as the desired therapeutical activity should be available tothe patient with the least undesirable side effects, a notable aspect ofthis invention involves the discovery of agonists with partial activityin those compounds with a 5α-pregnan-3α,20α-diol, 5β-pregnan-3α,20β-diolgroup or the derivatives and prodrugs of these compounds. In addition, asubset of neuroactive steroids other than these two groups also showpartial efficacy in TBPS assay (Table 1). For the patients who desireamelioration of anxiety or convulsions, hypnosis is undesired. For thepatients who desire amelioration of insomnia, anesthetic is undesired.The compounds and activities described as agonists with partial activityexpected to have the desired effect with minimal undesired effect.

To show the agonists with limited efficacy, the ability of5α-pregnan-3α,20α-diol and 5β-pregnan-3α,20α-diol to partially modulatethe [³⁵ S]TBPS binding even at very high concentrations is illustrated(FIG. 6).

In addition, the partial ability of these compounds to potentiateGABA-mediated enhancement of Cl⁻ current were compared to that of3α-hydroxy-5α-pregnan-20-one (FIG. 7) in Xenopus oocyte injected withhuman GABA_(A) receptor genes is also shown.

When Xenopus oocyte expression system was used to test the limitefficacy property of some neuroactive steroids, the following procedurewas performed. Xenopus laevis oocytes (stage VI) which had been"defolliculated" using the collagenase digestion method (3 hrs @18-23°C., 2 mg ml⁻¹ collagenase `A` in Barth's saline with Ca²⁺ salts omitted)were injected with cRNA transcripts of human GABA_(A) receptor subunitcomplex α1 β1 and γ1. The major GABA_(A) receptor complex is comprisedof αβγ subunits. Injected oocytes were individually maintained in96-well plates (200 μL per well of normal Barth's solution supplementedwith penicillin 50 IU ml⁻¹, streptomycin 50 mg ml⁻¹ and gentomycin 100mg ml⁻¹) for up to 9 days at 19-20° C. Agonist-induced currents wererecorded from Xenopus oocytes voltage clamped at a holding potential of-60 mV, using an Axoclamp 2 A (Axon Instruments) voltage clamp amplifierin the twin electrode voltage clamp mode. The voltage-sensing andcurrent-passing microelectrodes were filled with 3M KCl, and resistancesof 1-3M Ohams when measured in the standard extracellular saline. Theoocytes were continuously superfused with frog Ringer (120 mM NaCl; 2 mMKCl; 1.0 mM CaCl₂ ; 5 mM HEPES pH 7.4) at the rate of 5-7 ml min⁻¹ at rt(17-21° C.).

All drugs were applied via the perfusion system. Steroids (10⁻² M) wereprepared as concentrated stock solutions either in DMSO or ethanol andthen diluted in the Ringer solution at the appropriated concentration.The final DMSO and ethanol concentration was 0.2% v/v, a concentrationwhich had no effect upon GABA evoked responses. Stock solutions of allother drugs were made in Ringer solution. Membrane current responseswere low-pass filtered at 100 Hz and recorded onto magnetic tape usingan FM tape recorder (Racal Store 4DS) for subsequent analysis.

Compounds of and used in the present invention exhibit partial efficacyanalogous to those described above also shown in the above tables.

Benefits Over Progesterone

The correlations between reduced levels of progesterone and the symptomsassociated with PMS, PND, and catamenial epilepsy (Backstrom, et al.,1983; Dalton, K., 1984) led to the use of progesterone in theirtreatment (Mattson, et al., 1984; and Dalton, 1984). However,progesterone is not consistently effective in the treatment of theaforementioned syndromes. For example, no dose-response relationshipexists for progesterone in the treatment of PMS (Maddocks, et al.,1987). These results are predictable when considered in light of theresults of our in vitro studies which demonstrate that progesterone hasvery low potency at the GR complex, as seen in Table 1, compared tocertain metabolites of progesterone.

The beneficial effect of progesterone is probably related to thevariable conversion of progesterone to the active progesteronemetabolites. The use of specific progesterone metabolites in thetreatment of the aforementioned syndromes is clearly superior to the useof progesterone based upon the high potency and efficacy of themetabolites and their derivatives (See Gee, et al., 1987, and Table 1).

No Hormonal Side Effects

It has also been demonstrated that neuroactive steroids lack hormonalside effects by the lack of affinity for the progesterone and otherhormonal steroid receptors (Tables 2-5). The data presented wereobtained by performing assays in accordance with the proceduresdescribed in Gee, et al., 1988 previously to determine the effect ofprogesterone metabolites and their derivatives and the progestin R5020on the binding of [³ H]R5020 to the progesterone receptor in rat uterus(Gee et al., 1988).

³ H-progesterone (0.15 nM) was incubated with the rat uterus cytosol inthe presence of the test compounds. The specific bindings weredetermined after incubation and compared to the control incubationwithout the compounds. The data are expressed as percent inhibition ofbinding. If the compounds bind to the progesterone receptor with highaffinity, a 100% inhibition of binding would be expected at theconcentration tested.

Various hormonal activities of representative neuroactive steroids werefurther studied through testing their potential estrogenic,mineralocorticoid and glucocorticoid activities. These activities wereanalyzed by monitoring the ability of the compounds to inhibit bindingof the steroid hormones to their respective hormone receptors. Theresults are shown in Tables 3-5. They are expressed as percentinhibition of ³ H-ligand binding to the various steroid hormonereceptors for the compounds at 10⁻⁶ M. Control values are represented bythe binding in the absence of testing compounds.

In Table 3, rats were adrenalectomized 3 days prior to sacrifice. Toisolate the mineralocorticoid receptor, brain cytosol fractions wereprepared as describe in Gee, et al., 1988. The drugs were incubated with3 nM of ³ H-aldosterone (the specific ligand for the mineralocorticoidreceptor) in the presence of the selective type II agonist RU28362 (0.5μM) which blocks ³ H-aldosterone binding to the type II (glucocorticoid)receptors.

                  TABLE 2                                                         ______________________________________                                        Inhibition of .sup.3 H-Progesterone Binding to the                              Boving Uteral Progesterone Receptors                                            Competitor (10.sup.-6 M)                                                                           % of Inhibition                                      ______________________________________                                        R5020                100                                                        5α-pregnan-3α-ol-20-one 14                                        5α-pregnan-3α,21-diol-20-one 13                                   5α-pregnan-3α,20-diol 6                                           5α-pregnan-3α-ol-3α,-methyl-20-one 4                        5β-pregnan-3α,21-diole-20-one 6                                    5α-pregnan-3β,20-trimethyl-3α,20-diol 8                      5β-pregnan-3α,20α-diol 0                                     5β-pregnan-3α-ol-20-one 9                                          5α-pregnan-20-dimethyl-3α,20-diol 0                             ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Inhibition of .sup.3 H-Aldosterone Binding                                      to Hippocampal Mineralocorticoid Receptors                                      Competitor (10.sup.-6 M)                                                                           % of Inhibition                                      ______________________________________                                        Aldosterone          95.5                                                       5α-pregnan-3α,21-diol-20-one 76.7                                 5β-pregnan-3α,21-diol-20-one 13.8                                  5α-pregnan-3α,ol-20-one 0                                         5β-pregnan-3α,ol-20-one 0                                          5α-pregnan-3α,20α-diol 0                                    5β-pregnan-3α,20α-diol 0                                     5α-pregnan-3α,20-diol-20-dimethyl 0                               5α-pregnan-3α,ol-3β-methyl-20-one 3.2                        5α-pregnan-3β,20-trimethyl-3α,20-diol 0                    ______________________________________                                    

For Table 4, brain cytosol fractions were prepared as for Table 3, andthe compounds were incubated with 3 nM of ³ H-dexamethasone (thespecific ligand for the glucocorticoid receptor).

                  TABLE 4                                                         ______________________________________                                        Inhibition of .sup.3 H-Dexamethasone Binding to                                 Glucocorticoid Receptors                                                         Competitor (10.sup.-6 M)                                                                          % of Inhibition                                      ______________________________________                                        Dexamethasone        100                                                        5α-pregnan-3α,21-diol-20-one 29.5                                 5β-pregnan-3α,21-diol-20-one 8.2                                   5α-pregnan-3α-ol-20-one 8.7                                       5β-pregnan-3α-ol-20-one 5.9                                        5α-pregnan-3α,20α-diol 2.6                                  5β-pregnan-3α,20α-diol 1.4                                   5α-pregnan-20-dimethyl-3α,20-diol 2.6                             5α-pregnan-3α-ol-3β-methyl-20-one 0.6                      ______________________________________                                    

Table 5 shows the inhibition of ³ H-estradiol (the specific ligand forthe estrogen receptor) binding to bovine uteri cytosol, prepared aspreviously described (Gee, et al., 1988). ³ H-Estradiol (0.15 nM) wasincubated with the cytosol in the presence of the compounds.

                  TABLE 5                                                         ______________________________________                                        Inhibition of .sup.3 H-Estradiol Binding to Bovine                              Uteral Estrogen Receptors                                                       Competitor (10.sup.-6 M)                                                                           % of Inhibition                                      ______________________________________                                        17β-estradiol   100                                                        5α-pregnan-3α-ol-20-one 0                                         5α-pregnan-3α,21-diol-20-one 2                                    5α-pregnan-3α,20α-diol 0                                    5α-pregnan-3α-ol-3-methyl-20-one 0                                5β-pregnan-3α,21-diol-20-one 0                                     5α-pregnan-3β,20-trimethyl-3α,20-diol 0                      5β-pregnan-3α,20α-diol 8                                     5β-pregnan-3α-ol-20-one 0                                          5α-pregnan-20-dimethyl-3α,20-diol 0                             ______________________________________                                    

The results of these experiments clearly show that neuroactive steroidsdo not have a strong affinity for any of the above steroid receptors.Thus, they will not have predicted hormonal side-effects which wouldresult from such steroid receptor binding.

Anti-Convulsant Activity

Experiments were also performed to determine the physiological relevanceof neuroactive steroid and GABA receptor interactions by assessing theability of the compounds of and used in the invention to preventmetrazol induced convulsions in mice. Mice were injected with variousdoses of the test compounds of the invention, 10 minutes prior to theinjection of metrazol. The time to onset of myoclonus (presence offorelimb clonic activity) induced by metrazol was determined byobserving each mouse for a period of 30 minutes. In control mice,metrazol (85 mg/kg) will induce convulsion in 95% of the animals. Theability of several compounds of and used in the invention to protectmice from convulsion is shown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________    Antimetrazol Activity of Neuroactive Steroids in Mice                                                       Dose                                                                              %                                             Name Route Vehicle (mg/kg) Protected                                        __________________________________________________________________________    3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-5α-                                          IP 50% 10  75                                            pregnan-20-one  hpbcd                                                         3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-19-nor-5β- IP                                          50% 10 100                                    pregnan-20-one  hpbcd                                                         3β-(4'-Carboxyphenyl)ethynyl-3α-hydroxy-5β- IP 50% 10                                         18.75                                         pregnan-20-one ethyl ester  hpbcd                                             3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                          50% 10 100                                    20-one  hpbcd                                                                 3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-5β- IP 50% 10 75       pregnan-20-one  hpbcd                                                         3β-(4'-Acetoxybutyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                          50% 10 100                                    20-one  hpbcd                                                                 3α-Hydroxy-3β-(3'-methoxy-1'-propynyl)-5β- IP 50% 10 75       pregnan-20-one  hpbcd                                                         3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α- IP 50%                                        1 87.5                                       pregnan-20-one  hpbcd                                                         3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β- IP 50%                                        10 75                                         pregnan-20-one  hpbcd                                                         3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α- PO                                           water 10 80                                   pregnan-20-one 21-hemsuccinate salt                                           3β-(4'-Acetylphenylethynyl)-3α,12-dihydroxy-5β- PO                                            water 10 75                                   pregnan-20-one 21-hemsuccinate salt                                           3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan- IP                                          50% 10 50                                     11,20-dione  hpbcd                                                            3β-[3-(2-propynyloxy)propyn-1-yl]-3α-hydroxy-5β- IP 50%                                       10 50                                         pregnan-20-one  hpbcd                                                         3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-5α-pregnan- IP                                         50% 10 50                                     20-one  hpbcd                                                                 3α-Hydroxy-3β-(5'-oxo-1-hexynyl)-5β-pregnan-20- IP 50%                                        10 50                                         one cyclic 5'-(1,2-ethanediyl acetal)  hpbcd                                  3β-(4'-Biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20- IP                                          dmso 10 0                                     one                                                                           3β-(5-Acetylthien-2-yl)ethynyl-3α-Hydroxy-5β- IP 50% 10                                       25                                            pregnan-20-one  hpbcd                                                         3β-(4'-Trifuoromethylphenyl)ethynyl-3α-hydroxy- IP dmso 10                                         25                                            5β-pregnan-20-one                                                        3β-(4'-Chlorophenyl)ethynyl-3α-hydroxy-5β- IP dmso 10                                         37.5                                          pregnan-20-one                                                                3β-(5'-Hydroxypentyn-1'-yl)-3α-hydroxy-5β- IP 50% 10                                          12.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-(thien-2-yl)ethynyl-5β-pregnan-20- IP 50%                                       10 37.5                                       one  hpbcd                                                                    3β-(3'-Acetylphenyl)ethynyl-3α-hydroxy-5β- IP 50% 10 75       pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-[4'(R/S)-hydroxypentynyl]-5β- IP 50% 10                                         87.5                                          pregnan-20-one  hpbcd                                                         3β-(4'-Cyanophenyl)ethynyl-3α-hydroxy-5β- IP 50% 10                                           43.7                                          pregnan-20-one  hpbcd                                                         3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                          water 10 87.5                                 20-one 4'-hemisuccinate sodium salt                                           3α-Hydroxy-3β-[3'-(1H-pyrazol-1-yl)-1'-propynyl]- IP 50% 10                                        25                                            5β-pregnan-20-one  hpbcd                                                 3α-Hydroxy-3β-(4'-methylphenyl)ethynyl-5β- IP 50% 10 75       pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-(6-oxo-1-heptynyl)-5β-pregnan-20- IP 50%                                        10 62.5                                       one  hpbcd                                                                    3β-(5'-Acetoxypentyn-1'-yl)-3α-hydroxy-5β- IP 50% 10                                          12.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-(2'-pyridylethynyl)-5β-pregnan-20- IP 50%                                       10 37.5                                       one  hpbcd                                                                    3α-Hydroxy-3β-(5'-oxo-1-hexynyl)-5β-pregnan-20- IP 50%                                        10 25                                         one  hpbcd                                                                    3β-(4'-Cyano-1'-butynyl)-3α-hydroxy-5β-pregnan- IP 50%                                        10 12.5                                       20-one  hpbcd                                                                 3α-Hydroxy-3β-(3'-hydroxypropynyl)-5β-pregnan- IP 50%                                         10 25                                         20-one  hpbcd                                                                 3α-Hydroxy-3β-[3'(RS)-hydroxybutynyl]-5α- IP 50% 10 50       pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-[4'(R/S)-hydroxypentynyl]-5β- IP water 10                                       50                                            pregnan-20-one 4'(R/S)-hemisuccinate sodium salt                              3β-(5'-Cyanopentynyl)-3α-hydroxy-5β-pregnan-20- IP 50%                                        10 25                                         one  hpbcd                                                                    3α-Hydroxy-3β-[4'(R/S)-hydroxypentynyl]-5α- IP 50% 10                                        25                                            pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-[3'(RS)-hydroxybutynyl]-5β- IP 50% 10 25                                         pregnan-20-one  hpbcd                        3β-(5'-Hydroxypentyn-1'-yl)-3α-hydroxy-5β- IP 50% 10                                          37.5                                          pregnan-20-one 5'-hemisuccinate sodium salt  hpbcd                            3β-(3'-Acetoxypropyn-1'-yl)-3α-hydroxy-5β- IP 50% 10                                          12.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-3β-(2'-methoxyphenyl)ethynyl-5β- IP dmso 10                                        12.5                                          pregnan-20-one                                                                3β-(6'-Acetoxyhexyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                          50% 10 37.5                                   20-one  hpbcd                                                                 3α-Hydroxy-3β-[3'-(pyrid-4-yloxy)-1'-propynyl]-5β- IP                                         50% 10 12.5                                   pregnan-20-one  hpbcd                                                         3β-[2-(3',4'-Dimethoxyphenyl)ethyl]-3α-hydroxy- IP 50% 10                                          12.5                                          5β-pregnan-20-one  hpbcd                                                 3β-(3'-Hydroxy-3'-methylbutyn-1'-yl)-3α-hydroxy- IP 50% 10                                         43.7                                          5β-pregnan-20-one  hpbcd                                                 3α-Hydroxy-3β-[3'-(1H-1,2,3-triazol-1-yl)-1'- IP 50% 10 25                                          propynyl]-5β-pregnan-20-one                                             hpbcd                                         3α-Hydroxy-3β-[3'-(1H-1,2,4-triazol-1-yl)-1'- IP 50% 10 10                                          propynyl]-5β-pregnan-20-one                                             hpbcd                                         Sodium S-(3α-hydroxy-5β-pregnan-20-on-21-yl) IP water 10                                           37.5                                          thiosulfate                                                                   Sodium S-(3α-hydroxy-3β-methyl-5α-pregnan-20- IP water                                       10 62.5                                       on-21-yl) thiosulfate                                                         Sodium S-[3α-hydroxy-3β-(4'-hydroxybutynyl)-5β- PO                                            water 40 33.3                                 pregnan-20-on-21-yl] thiosulfate                                              Sodium S-(3α-hydroxy-3β-methoxymethyl-5α- IP water 10                                        62.5                                          pregnan-20-on-21-yl) thiosulfate                                              Sodium S-(3α-hydroxy-3β-trifluoromethyl-19-nor IP water 40                                         37.5                                          5β-pregnan-20-on-21-yl)thiosulfate                                       3α-Hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one IP 50% 10 50       hemisuccinate sodium salt  hpbcd                                              3α-hydroxy-21-(2'H-1,2,3,4-tetrazol-2'-yl)-5β- IP 50% 10                                           37.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(2H-1,2,3-triazol-2-yl)-5β-pregnan- IP 50% 10                                        100                                           20-one  hpbcd                                                                 3α-Hydroxy-21-[1H-(4-methyl-5-carboxyl)imidazol- IP 50% 10 37.5                                          1-yl)-5β-pregnan-20-one ethyl                                           ester  hpbcd                                  21-[1'-(4,5-Dichloro)imidazolyl]-3α-hydroxy-5β- IP 50% 10                                          37.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(1'-imidazolyl)-5α-pregnan-20-one IP 50% 10                                         50                                              hpbcd                                                                       3α-Hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one IP 50% 10                                          12.5                                            hpbcd                                                                       3β-Ethynyl-3α-Hydroxy-21-(1'-imidazolyl)-5β- IP 50% 10                                        50                                            pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(1H-3,5-dimethylpyrazolyl)-5β- IP 50% 10 50                                           pregnan-20-one  hpbcd                        3α-Hydroxy-21-(1'-imidazolyl)-3β-methyl-5α- IP 50% 10                                        75                                            pregnan-20-one  hpbcd                                                         3β-Ethynyl-3α-Hydroxy-21-(1'-pyrazolyl)-5β- IP 50% 10                                         62.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(1'-pyrazolyl)-3β-methyl-5α- IP 50% 10                                         87.5                                          pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(pyrazol-1-yl)-5β-pregnan-20-one IP 50% 10                                           62.5                                            hpbcd                                                                       3α-Hydroxy-3β-methyl-21-(1',2',4'-triazolyl)-5α- IP                                          50% 10 87.5                                   pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(1',2',4'-triazol-1-yl)-5β-pregnan- IP 50% 10                                        37.5                                          20-one  hpbcd                                                                 21-[1'-(4,5-Dicyano)imidazolyl]-3α-hydroxy-5β- IP 50% 10 50                                         pregnan-20-one  hpbcd                        3α-Hydroxy-21-[1H-(2-methyl)imidazol-1-yl)-5β- IP 50% 10 6.2       pregnan-20-one  hpbcd                                                         3α-Hydroxy-21-(1'-pyrazolyl)-3β-trifluoromethyl- IP 50% 10                                         12.5                                          5β-19-nor-pregnan-20-one  hpbcd                                          3α-Hydroxy-21-(1'-imidazolyl)-3β-trifluoromethyl- IP 50% 10                                        50                                            5β-19-nor-pregnan-20-one  hpbcd                                        __________________________________________________________________________

The ability of neuroactive steroids to protect animals against otherchemical convulsants was further demonstrated for3α-hydroxy-5α-pregnan-20-one, 3α,21-dihydroxy-5α-pregnan-20-one and3α-hydroxy-3β-methyl-5α-pregnan-20one. The anticonvulsant tests aresimilar to that described above. The following chemical convulsants are:metrazole (85 mg/kg); (+)bicuculline (2.7 mg/kg); picrotoxin (3.15mg/kg); strychnine (1.25 mg/kg); or vehicle (0.9% saline). Immediatelyafter the injection of convulsant or vehicle, the mice were observed fora period of 30 to 45 minutes. The number of animals with tonic and/orclonic convulsions was recorded. In the maximal electroshock test, 50 mAof current at 60 Hz was delivered through corneal electrodes for 200msec to induce tonic seizure. The ability of compounds to abolish thetonic component was defined as the endpoint. General CNS depressionpotential was determined by a rotorod test 10 minutes after theinjection of compounds where the number of mice staying on a rotating (6rpm) rod for 1 minute in one of the three trials was determined. TheED₅₀ (the dose at which the half-maximal effect occurs) was determinedfor each screen and are presented in Table 7, infra. The resultsdemonstrate that neuroactive steroids, in comparison to other clinicallyuseful anti-convulsants, are highly effective with profiles similar tothat of the BZ clonazepam. These observations demonstrate thetherapeutic utility of these compounds as modulators of brainexcitability, which is in correspondence with their high affinityinteraction with the GR complex in vitro.

                  TABLE 7                                                         ______________________________________                                        Anticonvulsant Activity of Exemplified                                          Neuroactive Steroids and those of Selected Clinically Useful                  Anticonvulsants in Mice                                                       ED.sub.50 (mg/Kg)                                                             Compound       RR     MES  MTZ  BIC   PICRO STR                             ______________________________________                                        3α5α.sup.(a) -P                                                                30     28.6   4.9  12.3  10.2  >300                                5α-THDOC.sup.(a) 22.9 26.7 8.1 17.8 5.6 >300                            3α-hydroxy-3β-methyl- 246.2 >100 6.3 61.9 35.4 >100                5α-pregnan-20 one.sup.(b)                                               Clonazepam* 0.184 93 0.009 0.0086 0.043 NP                                    Phenobarbital* 69 22 13 38 28 95                                              Phenytoin* 65 10 NP NP NP **                                                  Progabide*** -- 75 30 30 105 75                                               Valproate* 426 272 149 360 387 293                                          ______________________________________                                         The abbreviations are RR (Rotorrod); MES (maximal electroschock); MTZ         (metrazol); BIC (bicuculline); PICRO (picrotoxin); STR (styrchnine); NP       (no protection)                                                               .sup.(a) Dissolved in 20% hydroxypropylcyclodextrin in water. The route o     administration for steroids and convulsants was i.p. and s.c.,                respectively.                                                                 *Anticonvulsant data are from Swinyard & Woodhead, General principles:        experimental detection, quantification and evaluation of anticonvulsants,     in Antiepileptic Drugs, D. M. Woodbury, J. K. Penry, and C. E. Pippenger,     eds. p. 111, (Raven Press, New York), 1982.                                   .sup.(b) Vehicle contained 0.32% hydroxypropylmethyl cellulose and 4%         tween 80 in saline.                                                           **Maximum protection of 50% at 55-100 mg/kg.                                  ***The chemical convulsants in the progabide studies were administered        i.v., all data from Worms et al., Gammaaminobutyric acid (GABA) receptor      stimulation. I. Neuropharmacological profiles of progabide (SL 76002) and     SL 75102, with emphasis on their anticonvulsant spectra, Journal of           Pharmacology and Experimental Therapeutics 220: 660-671 (1982).          

Anxiolytic Effects

The following experiments demonstrate that the progesterone metabolites,3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one are effectiveanxiolytics in four animal models of human anxiety that measure thebehavioral effects of anxiolytic compounds. It is to be understood thatthese two compounds describe the invention by way of illustration. Dataon their synthetic derivatives in these measurements also is presentedin Table 8-10. The four animal models used to measure the behavioraleffects of anxiolytic compounds are: 1) light/dark transition test; 2)elevated plus-maze; 3) Geller-Seifter conflict test and 4) Vogel test.

a) Light/dark Transition Test

The light/dark transition test (Crawley and Goodwin, "Preliminary reportof a simple animal behavior model for th anxiolytic effect ofbenzodiazepines", Pharmacol. Biochem. Behav. 13:67-70 (1980)) is basedon the observation that rodents naturally tend to explore novelenvironments, but open, brightly lit arenas are aversive to the rodentsand inhibit exploratory behavior (Christmas and Maxwell, "A comparisonof effects of some benzodiazepines and other drugs on aggressive andexploratory behavior in mice and rats", Neuropharmacol. 9:17-29 (1970);File, "The use of social interaction as a method of detecting anxiolyticactivity of chlordiazepoxide-like drugs", J. Neurosci. Meth. 2:219-238(1980)). A variety of clinically established anxiolytics includingdiazepam, clonazepam and pentobarbital have been shown to increase thenumber of transitions between the light box and the dark box, whereasnon-anxiolytic drugs do not demonstrate this behavioral effect (Crawleyet al., "Absence of intrinsic antagonist actions of benzodiazepineantagonists on an exploratory model of anxiety in the mice",Neuropharmacol. 23:531-537 (1984)).

Male N.I.J. Swiss-Webster mice (Harlan, Harlan, Indianapolis, Ind.)weighing 15-20 g were housed four per cage in polyethylene cages withsawdust bedding. The colony room was environmentally controlled (22° C.)with a 12 hr light/dark cycle (0600-1800 hr). Food and water wereavailable ad libitum, except during testing. The experiments were runfrom 0700-1500 hr and groups were counterbalanced for time of dayeffects. Mice were only administered drug or vehicle once.

The method used was a modification of methods previously described(Wieland et al., "Anxiolytic activity of progesterone metabolite5α-pregnan-3α-ol-20-one", Br. Res. 565:263-268 (1991)). The apparatusincluded two 2-compartment automated test chambers (Model RXYZCM16,Omnitech Electronics, Columbus, Ohio). The open compartment wasconnected to the enclosed compartment via a 7.5×7.5 cm passageway. Theopen compartment was brightly lit using a 200 W incandescent light bulb.The experimental room was kept dark. Interruptions of the infrared beamsin either chamber were automatically recorded by being linked to acomputer through a Digiscan Analyzer (Omnitech Electronics) and the datawas analyzed using the Integrated Lab Animal Monitoring System (OmnitechElectronics). N.I.H. Swiss-Webster mice were administered vehicle ortest drug intraperitoneally (IP), 10 min later they were placed in thecenter of the lit compartment. The number of transitions between the litand dark chambers, total activity in the lit chamber and the time spentin the lit chamber were measured during a 10 min test period.

FIG. 8 shows the effects of 3α-OH-5α-pregnan-20-one and3α-OH-5β-pregnan-20-one in the light-dark transition test. Bothcompounds produced a significant dose-response curve in relation to thenumber of transitions between the dark box and the light box. Post-hoccomparisons showed that the number of the crossing for doses for both3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one were significantlyincreased at doses tested from control (Dunnett's t-test).

In addition both 3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-oneproduced significant (p<0.01) increases in activity at 10 & 20 mg/kg ascompared to control groups (Dunnett's t-test). There were no significantdifferences between the two compounds at any dose tested.

b) Elevated Plus-Maze

The theoretical basis for the elevated plus-maze test is similar to thatof the light/dark transition test. As it was described previously(Pellow et al. "Validation of open:closed arm entries in an elevatedplus-maze as a measure of anxiety in the rat", J. Neurosci. Meth.14:149-167 (1985)), the elevated plus-maze apparatus is designed toutilize the mice's natural aversion to open spaces. The apparatusconsists of two open-arms and two enclosed-arms. The elevated plus-mazetest allows for two measures of anxiety, the number of entries into theopen-arms and the time spent on the open-arms, both expressed as apercentage of the total number of entries and time spent in/on both theopen-arms and enclosed-arms.

Male N.I.H. Swiss-Webster mice (Harlan, Indianapolis, Ind.) weighing15-20 g were housed four per cage in polyethylene cages with sawdustbedding. The colony room was environmentally controlled (22° C.) with a12 hr light/dark cycle (0600-1800 hr). Food and water were available adlibitum, except during testing. The experiments were run from 0700-1500hr and groups were counterbalanced for time of day effects. Mice wereonly administered drug or vehicle once.

The method used was previously described (Lister, "The use of Plus-Mazeto measure anxiety in the mouse", Psychlopharmacol. 92:180-185 (1987)).The apparatus included two open arms perpendicular to two enclosed armselevated 50 cm from the floor. Each arm was 50 cm long and the walls ofthe enclosed arms were 40 cm tall. The maze was made completely of blackplexiglass. Incandescent 200 W light bulbs were above each of the openarms to produce a strong contrast between the open arms and the enclosedarms.

Ten minutes after an injection, the N.I.H. Swiss-Webster mice wereplaced in the center of the plus-maze facing an open arm. During the 5min test period, the number of entries onto the open arms and theenclosed arms, and the time spent in the open arms and enclosed armswere measured. All four paws had to be within an arm for the dependentvariable to be measured. Therefore, the time spent in the center of themaze is not counted, so the total time spent in the open arms and theenclosed arms may not equal 5 min. The effects of3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one in the elevatedplus-maze test are shown in FIG. 9A. Both compounds demonstrate increaseproportion of entries into the open-arms across doses.3α-OH-5α-pregnan-20-one produced significant increase in entries at 20mg/kg (p≦0.05), whereas 3α-OH-5β-pregnan-20-one produced significantincreases in entries at 5 mg/kg (p≦0.05), 7.5 mg/kg (p≦0.01), and 10mg/kg (p≦0.01).

In addition, 3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-oneproduced dose-dependent increases in the time spent in the open-arms(FIG. 9B). 3α-OH-5α-pregnan-20-one produced significant increases intime spent on the open-arms at 10 mg/kg (p≦0.01), whereas3α-OH-5β-pregnan-20-one produced significant increases in time spent onthe open-arms at 7.5 mg/kg (p≦0.01) and 10 mg/kg (p≦0.01).

Table 8 shows the summary of anxiolytic activities of compounds of andused in the invention using the elevated plus-maze under the sameconditions described above.

                                      TABLE 8                                     __________________________________________________________________________    Anxiolytic Activity in Plus Maze in Mice                                                                Dose                                                  Name Route mg/kg Vehicle % Control                                          __________________________________________________________________________    3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-                                  IP 10  50% 175.7                                         20-one   hpbcd                                                                3β-(4'-Acetylphenyl)ethynyl-3α-hydroxy-19-nor-5β- IP 10                                       50% 191                                       pregnan-20-one   hpbcd                                                        3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-5β-pregnan- IP 10                                       50% 141                                       20-one   hpbcd                                                                3β-(4'-Acetoxybutyn-1'-yl)-3α-hydroxy-5β-pregnan- IP 10                                       50% 159                                       20-one   hpbcd                                                                3α-Hydroxy-3β-(3'-methoxy-1'-propynyl)-5β- IP 10 50%                                          134                                           pregnan-20-one   hpbcd                                                        3β-[3-(2-Propynyloxy)propyn-1-yl]-3α-hydroxy-5β- IP 10                                        50% 178                                       pregnan-20-one   hpbcd                                                        3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-5α-pregnan- IP                                         10 50% 186                                    20-one   hpbcd                                                                3β-(4'-Biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20- IP 10                                       dmso 111                                      one                                                                           3β-(5-Acetylthien-2-yl)ethynyl-3α-Hydroxy-5β- IP 10 50%                                       83                                            pregnan-20-one   hpbcd                                                        3β-(4'-Chlorophenyl)ethynyl-3α-hydroxy-5β-pregnan- IP                                         10 dmso 161                                   20-one                                                                        3β-(5'-Hydroxypentyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                         10 50% 137                                    20-one   hpbcd                                                                3α-Hydroxy-3β-(thien-2-yl)ethynyl-5β-pregnan-20- IP 10                                        50% 148                                       one   hpbcd                                                                   3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α- IP  1                                        50% 150                                       pregnan-20-one   hpbcd                                                        3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5β- IP 10                                         50% 115                                       pregnan-20-one   hpbcd                                                        3β-(4'-Acetylphenylethynyl)-3α,21-dihydroxy-5α- PO 10                                        water 166                                     pregnan-20-one 21-hemsuccinate salt                                           3β-(4'-Acetylphenylethynyl)-3α-21-dihydroxy-5β- PO 10                                         water 248                                     pregnan-20-one 21-hemsuccinate salt                                           3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5α-pregnan- IP                                         10 50% 119                                    11,20-dione   hpbcd                                                           3β-(3'-Acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan- IP                                         10 50% 143                                    20-one   hpbcd                                                                3β-(4'-Cyanophenyl)ethynyl-3α-hydroxy-5β-pregnan- IP 10                                       50% 169                                       20-one   hpbcd                                                                3β-(4'-Hydroxybutyn-1'-yl)-3α-hydroxy-5β-pregnan- IP 10                                       water 149                                     20-one 4'-hemisuccinate sodium salt                                           3α-Hydroxy-3β-[3'-(1H-pyrazol-1-yl)-1'-propynyl]- IP 10 50%                                        116                                           5β-pregnan-20-one   hpbcd                                                3α-Hydroxy-3β-(4'-methylphenyl)ethynyl-5β-pregnan- IP                                         10 50% 148                                    20-one   hpbcd                                                                3α-Hydroxy-3β-(6-oxo-1-heptynyl)-5β-pregnan-20- IP 10                                         50% 130.5                                     one   hpbcd                                                                   3α-Hydroxy-3β-(2'-pyridylethynyl)-5β-pregnan-20- IP 10                                        50% 123                                       one   hpbcd                                                                   3β-(4'-Cyano-1'-butynyl)-3α-hydroxy-5β-pregnan-20- IP                                         10 50% 184                                    one   hpbcd                                                                   3α-Hydroxy-3β-(3'-hydroxypropynyl)-5β-pregnan-20- IP 10                                       50% 128                                       one   hpbcd                                                                   3α-Hydroxy-3β-[4'(R/S)-hydroxypentynyl]-5α- IP 10 50%                                        102                                           pregnan-20-one   hpbcd                                                        3α-Hydroxy-3β-[3'(RS)-hydroxybutynyl]-5β-pregnan- IP 10                                       50% 137.7                                     20-one   hpbcd                                                                3β-(5'-Hydroxypentyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                         10 50% 155                                    20-one 5'-hemisuccinate sodium salt   hpbcd                                   3β-(3'-Acetoxypropyn-1'-yl)-3α-hydroxy-5β-pregnan- IP                                         10 50% 109                                    20-one   hpbcd                                                                3α-Hydroxy-3β-(2'-methoxyphenyl)ethynyl-5β- IP 10 dmso                                        152                                           pregnan-20-one                                                                3β-(6'-Acetoxyhexyn-1'-yl)-3α-hydroxy-5β-pregnan- IP 10                                       50% 206                                       20-one   hpbcd                                                                3α-Hydroxy-3β-[3'-(1H-1,2,3-triazol-1-yl)-1'- IP 10 50% 116                                         propynyl]-5β-pregnan-20-one                                             hpbcd                                         3α-Hydroxy-3β-[3'-(1H-1,2,4-triazol-1-yl)-1'- IP 10 50% 122                                         propynyl]-5β-pregnan-20-one                                             hpbcd                                         Sodium S-(3α-hydroxy-5β-pregnan-20-on-21-yl) IP 10 50% 143                                          thiosulfate   hpbcd                          Sodium S-(3α-hydroxy-3β-methyl-5α-pregnan-20-on- IP 10                                       water 125                                     21-yl) thiosulfate                                                            Sodium S-[3α-hydroxy-3β-(4'-hydroxybutynyl)-5β- IP 10                                         water 135                                     pregnan-20-on-21-yl] thiosulfate                                              Sodium S-(3α-hydroxy-3β-methoxymethyl-5α- IP 10 water                                        126                                           pregnan-20-on-21-yl) thiosulfate                                              Sodium S-(3α-hydroxy-3β-trifluoromethyl-19-nor-5β- IP                                         10 50% 139                                    pregnan-20-on-21-yl)thiosulfate   hpbcd                                       3α-hydroxy-21-(2'H-1,2,3,4-tetrazol-2'-yl)-5β- IP 10 50% 117       pregnan-20-one   hpbcd                                                        3α-Hydroxy-21-(2H-1,2,3-triazol-2-yl)-5β-pregnan- IP 10 50%                                        164                                           20-one   hpbcd                                                                3α-Hydroxy-21-[1H-(4-methyl-5-carboxyl)imidazol-1- IP 10 50% 112                                         yl)-5β-pregnan-20-one ethyl ester                                         hbpcd                                       3α-Hydroxy-21-(1'-imidazolyl)-5α-pregnan-20-one IP 10 50%                                         141                                              hpbcd                                                                      3α-Hydroxy-21-(1'-imidazolyl)-5β-pregnan-20-one IP 10 50%                                          138                                              hpbcd                                                                      3β-Ethynyl-3α-Hydroxy-21-(1'-imidazolyl)-5β- IP 10 50%                                        179                                           pregnan-20-one   hpbcd                                                        3α-Hydroxy-21-(1H-3,5-dimethylpyrazolyl)-5β- IP 10 50% 128                                          pregnan-20-one   hpbcd                       3α-Hydroxy-21-(1'-imidazolyl)-3β-methyl-5α- IP 10 50%                                        144                                           pregnan-20-20-one   hpbcd                                                     3β-Ethynyl-3α-Hydroxy-21-(1'-pyrazolyl)-5β- IP 10 50%                                         180                                           pregnan-20-one   hpbcd                                                        3α-Hydroxy-21-(1'-pyrazolyl)-3β-methyl-5α-pregnan- IP                                        10 50% 154                                    20-one   hpbcd                                                                3α-Hydroxy-21-(pyrazol-1-yl)-5β-pregnan-20-one IP 10 50% 129          hpbcd                                                                      3α-Hydroxy-3β-methyl-21-(1',2',4'-triazolyl)-5α- IP 10                                       50% 153                                       pregnan-20-one   hpbcd                                                        3α-Hydroxy-21-(1',2',4'-triazol-1-yl)-5β-pregnan-20- IP 10                                         50% 135                                       one   hpbcd                                                                   3α-Hydroxy-21-[1H-(2-methyl)imidazol-1-yl)-5β- IP 10 50% 96                                         pregnan-20-one   hpbcd                     __________________________________________________________________________

c) Geller-Seifter Conflict Test

This animal model of human anxiety utilizes a conditioned state ofconflict in rats to ascertain the anxiolytic properties of drugs. Ratsare conditioned to bar press for positive reinforcement under twoschedules of behavior (Geller and Seifter, "The effects of meprobamate,barbiturates, d-amphetamine and promazine on experimentally inducedconflict in the rat," Psychopharmacologia 1:482-492 (1960)). The firstincludes bar pressing under a variable ratio schedule withoutpunishment. The second component is a fixed ratio schedule with each barpress resulting in a positive reinforcement and a punishment. Thepunished component produces a state of conflict within the animal. Theunpunished component allows for the observation of any responsedepressant effects a drug may possess. An anxiolytic response wouldincrease the punished responding without affecting the unpunishedresponding.

Male albino Sprague-Dawley rats (Charles River Labs, Wilmington, Mass.)weighing 250-300 g were used for conflict experiments and were kept on arestricted diet of Purina Lab Chow food pellets with water available atall times to maintain body weight at 85% of their free-feeding youngadult levels. Rats were housed individually under a 12-hour light-darkcycle with lights on from 0700-1900.

The anti-anxiety (punishment-lessening) and response depressant effectsof 3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one were measured inrats by the conflict test of Geller and Seifter (1960). In this 63-mintest, hungry rats perform a lever-press response to obtain a sweetenedmilk reward. The reinforcement schedule consists of punishment andnonpunishment components, alternating approximately every 15 min. Ratswere trained in test chambers (Coulbourn instruments) with a levermounted in one wall, a small dipper that delivered the 0.1-mL milkreward (1 part Eagle condensed:milk 2 parts water), and a metal gridfloor through which the foot-shock punishment was administered. A DECPDP 11/73 minicomputer running SKED (State Systems) was used forprogramming and recording.

Rates initially learned to respond on a continuous reinforcementschedule and progressed rapidly to 30-sec, 1-min, and 2-min variableinterval (VI) schedules. On the continuous reinforcement schedule, ratsreceived milk reward following every lever press; on the VI schedules,milk rewards were available at infrequent and variable intervals,eventually at an average of once every 2 min. Four 3-min "conflict"periods were then introduced on the unpunished VI baseline; the firststarted after 3 min of VI performance and the others were alternatedbetween 12-min periods of VI responding. During conflict periods, whichwere signalled by the presentation of a light and a tone, the continuousreinforcement schedule was again in force and each lever press deliveredboth a milk reward and a brief (0.25 msec) foot-shock punishment. Shockintensity was 0.2 mA initially, and was increased daily in increments of0.02 mA in order to gradually suppress lever pressing to 5 responses orless per conflict period. This training took 4-6 weeks, after whichstable low rates of response were observed during conflict periods andstable high rates in the nonpunishment periods. Drug-induced increasesin the rate of punished responses were taken as an index of antianxietyactivity, while decreases in the rate of unpunished responses were takenas an index of response depression or sedation.

The effects of 3α-OH-5α-pregnan-20-one and 3α-OH-5β-pregnan-20-one inthe conflict test are summarized in FIG. 10. Both compounds producedlarge increases in the rate of punished responses, suggesting that bothwould be active as antianxiety agents. The peak effect of3α-OH-5β-pregnan-20-one was observed at 2 mg/kg and that of3α-OH-5α-pregnan-20-one at 4.4 mg/kg following subcutaneousadministration. (For statistical analysis and because of the smallnumber of tests at each dose, all tests with each compound were combinedfor comparison against vehicle control tests, using a t-test for relatedmeasures: for 3α-OH-5α-pregnan-20-one, p<0.02; for3α-OH-5β-pregnan-20-one, p<0.008).

Table 9 shows the summary of anxiolytic activities of compounds of andused in the invention using Geller-Seifter test under the experimentalconditions described above.

                  TABLE 9                                                         ______________________________________                                        Anxiolytic Activity in Geller/Seifter in Rats                                                                          Geller/                                    Seifter                                                                      Dose (% of                                                                 Compounds Route Vehicle (mg/kg) control)                                    ______________________________________                                        3α-Hydroxy-3β-methoxymethyl-                                                       IP      50%     10     958                                      5α-pregnan-20-one  hpbcd                                                11α-N,N-Dimethylamino-3α- IP citrate 20 145                       hydroxy-3β-trifluoromethyl-5β-                                      pregnan-20-one                                                                Sodium S-(3α-hydroxy-3β- PO water 32 4487.5                        methoxymethyl-5α-pregnan-20-                                            on-21-yl)thiosulfate                                                          3α-hydroxy-3β-ethoxymethyl- IP 50% 40 3743                         5α-pregnan-20-one  hpbcd                                              ______________________________________                                    

d) Vogel Test

The Vogel test is based on the development of a conflict between ahighly motivated behavior and an aversion. For this test, the strongmotivation is thirst. The animal is water deprived for 12-16 hrs toproduce the motivation to drink. During the training period the animalsare exposed to the testing environment so they become accustomed to thedrinking spout and minimize the fear of a novel environment. Followingtraining, the animals are allowed access to water for 2 hrs. During thistime, the animals will drink and eat their normal amount of water andfood, compensating for the deprivation time. However, this schedulestill produces a strong motivation to drink during the testing period.

Having been deprived of water for twelve to sixteen hours, an animal isplaced in a test cage where it is allowed to drink freely for fiveminutes. This period is used to habituate the animal to the environmentand the drinking spout. Following the training period, animals haveaccess to water and food in their home cage for 2 hrs. Food is availableat all times. Twenty-four hours later, drug is administered to theanimal intracerebroventricularly.

After an indicated delay started from the time of injection the animalis again placed in the test cage for ten minutes. A computer counts eachtime the animal licks, and after every twentieth lick administers a mildelectric stimulus across the tongue and/or feet. The electrical stimulusconsists of a 0.6 mA current with a duration of 100 msec. This procedureproduces a state of conflict for the animal that is reduced by theadministration of clinically used anxiolytic agents (i.e., Valium). Fordose-response curves, separate groups of animals are injected withincreasing doses of test drug and are tested at a predetermined time.

Data of representative compounds using these measurements are summarizedin Table 10.

                  TABLE 10                                                        ______________________________________                                        Anxiolytic Activity in Vogel Test in Rats                                                                              Vogel                                     Dose (% of                                                                 Compounds Route Vehicle (μg/kg) control)                                 ______________________________________                                        3α,20α-Dihydroxy-2β-                                                         i.c.v.  g-CD    10     169.0                                    isopropoxy-5α-pregnane                                                  3α,20-Dihydroxy-20-methyl-5α- i.c.v. g-CD 20 179.0                pregnane                                                                      3α,20α-Dihydroxy-21-methyl- i.c.v. g-CD 10 157.9                  5α-pregnane                                                             3α,20α(S)-Dihydroxy-5α- i.c.v. g-CD 10 193.0                pregnane                                                                      3α-Hydroxy-5α-pregnan-20-one i.c.v. g-CD 10 431.1                 3α,20α-Dihydroxy-5α-pregnane i.c.v. g-CD 10 283.3                                                 2β-Fluoro-3α,20α-                                           dihydroxy- i.c.v. g-CD 20 264.9                                                5α-pregnane                       3α,20α-Dihydroxy-21-ethyl-5α- i.c.v. g-CD 20 225.8                                                pregnane                                3α,20α-Dihydroxy-5α-pregnane i.c.v. g-CD 20 267.3         ______________________________________                                    

Prodrugs

Anti-convulsant and anxiolytic activities of prodrugs of the basiccompounds 3α-hydroxy-5α-pregnan-20-one and3α,21-dihydroxy-5α-pregnan-20-one and their derivatives were assessed asusing the same procedures described above. Percent protection by severalprodrugs of 3α-hydroxy-5α-pregnan-20-one against metrazol-inducedseizures was plotted against time after administration of the compounds.(FIG. 11 and Table 11).

Modification of the basic compounds 3α-hydroxy-5α-pregnan-20-one and3α,21-dihydroxy-5α-pregnan-20-one at the 3α and 21 hydroxyls withvarious esters maintains their biological activity and in some casessuch modification increased the time of protection provided by thecompound. Thus, the compounds of this invention can be modified toprovide anti-convulsant and anxiolytic activities over a period of time,with varying degrees of protection.

                  TABLE 11                                                        ______________________________________                                        Anti-Metrazol Activity of Prodrug Esters of                                     3α-Hydroxy-5α-pregnane-20-one (3α-(RCOO)-5α-         pregnan-20-one)                                                                                   % Protection 60 mg/kg 1 hr,                                                    R IP                                                    ______________________________________                                        Methyl           25                                                             Ethyl 75                                                                      Propyl 75                                                                     Butyl 33                                                                      2-Propyl 75                                                                   4-Heptyl 16 (4 hour)                                                          Cyclobutyl 17                                                                 Phenyl 33                                                                     4-Chlorophenyl 50                                                             4-Methoxyphenyl 17                                                            3-Pyridyl 50 (20 hour)                                                        3-(1-Methyl-1,4-dihydropyridinyl) 63 (20 hour)                              ______________________________________                                    

In contrast to benzodiazepines, neuroactive steroids can also induceanesthesia. Their ability to induce anesthesia is thought to be due totheir ability to open the chloride ion channel in the absence of GABA,which is a property not possessed by benzodiazepines. Therefore,neurosteroids can act directly in the absence of GABA, at the receptor,and also "indirectly", in the presence of GABA. This "indirect" actionis called "modulating" the receptor. (Lambert, et al., "Actions ofsynthetic and endogenous steroids on the GABA_(A) receptor," TrendsPharmacology Science 8: 224-227 (1987).)

The compounds of and used in the invention can also be used foranesthetic indications at high doses. However, the preferred route ofadministration to induce anesthesia is intravenous (i.v.)administration. In animals, a drug's anesthetic properties is measuredby the drug's ability to produce a loss-of-righting reflex. Theloss-of-righting reflex is defined as the inability of an animal toright itself within 30 seconds when placed on its back. Mice wereadministered drug i.v. in the lateral tail vein. Followingadministration, mice were placed on their backs and observed forloss-of-righting reflex. Illustrative results are presented in Table 12.

                  TABLE 12                                                        ______________________________________                                        Anesthetic Activity of Neuroactive Steroids                                     in Mice                                                                                                             Loss-of-                                   Dose Righting                                                              Compounds Route Vehicle (mg/kg) Reflex                                      ______________________________________                                        3α,21-Dihydroxy-3β-ethynyl-                                                       iv     20%       10    100                                       5β-pregnan-20-one  cremophor                                             3β-(Chloroethynyl)-3α- iv micronizing 20 100                       hydroxy-5β-pregnan-20-one  solution                                      3β-Ethynyl-3α-hydroxy-5β- iv 10% hpbcd 30 100                 pregnan-20-one                                                                3α-Hydroxy-3β-methyl-5α- iv micronizing 50 100                                                    pregn-16-en-20-one  solution                                                  3α-Hydroxy-5α-pregn-9-e                                          n iv micronizing 10 100                   20-one  solution                                                              3α-Hydroxy-17(Z)- iv micronizing 5  75                                  methoxymethylene-19-nor-  solution                                            5α-androstane                                                           3α-Hydroxy-3β-methyl-5β- iv micronizing 2.5 100                                                    pregnan-20-one  solution                 2β-Ethoxy-3α-hydroxy-5α- iv 20% 5 100                        pregnan-20-one  cremophor                                                     2β-Fluoro-3α-hydroxy-5α- iv micronizing 5 100                pregnan-20-one  solution                                                      3α-Hydroxy-3β-methyl-21- iv micronizing 20 100                     methoxymethyl-5α-pregnan-  solution                                     20-one                                                                      ______________________________________                                    

It is anticipated that prodrugs, with similar modifications as describedabove, of compounds of and used in the invention will have activity asprodrugs of 3α-hydroxy-5-reduced-pregnanes.

While the preferred embodiments have been described and illustrated,various substitutions and modifications may be made thereto withoutdeparting from the scope of the invention. Accordingly, it is to beunderstood that the present invention has been described by way ofillustration and not limitation.

What is claimed is:
 1. A compound of the formula: ##STR2## wherein: R ishydrogen, halogen, lower alkoxy, alkyl, optionally substituted 1-alkynylor substituted alkyl;R₁ is a substituted aralkynyl, arylalkyl,arylalkenyl, aryl, optionally substituted aralkylalkynyl,alkanoyloxyalkynyl, optionally substituted heteroaryloxyalkynyl,oxoalkynyl or a ketal thereof, cyanoalkynyl, optionally substitutedheteroarylalkynyl, hydroxyalkynyl, alkoxyalkynyl, aminoalkynyl,acylaminoalkynyl, mercaptoalkynyl, hydroxyalkynyl dioic acid hemi-esteror a salt thereof, or alkynyloxyalkynyl; R₂ is hydrogen, hydroxy,alkoxy, alkanoyloxy, carbalkoxyl, a keto group or amino group; R₃ is anacetyl group, a ketal of an acetyl group; an alkoxyacetyl group, analkylthioacetyl group, an alkylsulfinylacetyl group, analkylsulfonylacetyl group, an aminoacetyl group, a trifluoroacetylgroup; a hydroxyacetyl group; an alkoxyalkylacetyl group; a hydroxyalkylgroup; a hydroxyacetyl dioic acid hemi-ester salt; an alkanoyloxyacetylgroup; a sulfoxyacetyl group; an alkylacetyl group; a haloacetyl group;an ethynyl group; an optionally substituted heteroaralkylacetyl groupwhich may also optionally be substituted on the alkylene with a hydroxy,alkoxy, alkanoyloxy or carbalkoxyl group; an optionally substitutedheterocyclic-acetyl group; an acetyl thiosulfate salt; a cyano group; amethylene group (together with R₇); an alkylmethylene group (togetherwith R₇); or an alkoxymethylene group (together with R₇); R₄ is hydrogenor methyl, R₅ is hydrogen; R₆ is hydrogen, alkanoyl, aminocarbonyl oralkoxycarbonyl; R₇ is hydrogen, halogen, hydroxy, alkoxy, alkanoyloxy,carbalkoxyl, a methylene group (together with R₃), or an alkoxymethylenegroup (together with R₃); R₈ is hydrogen or halogen; R₉ is hydrogen,halogen, alkyl, alkoxy, arylalkoxy or amino; and R₁₀ is hydrogen,halogen; alkyl, haloalkyl, hydroxy, alkoxy, alkanoyloxy, carbalkoxyl,cyano, thiocyano or mercapto;with the proviso that when R₃ is anacetylthiosulfate salt or when R is an optionally substituted 1-alkynylgroup, then R₁ may further be hydrogen, alkyl, alkenyl, aryl, aralkyl,alkynyl, optionally substituted aralkynyl, alkoxyalkyl, aminoalkyl,cyano, cyanoalkyl, thiocyanoalkyl, or azidoalkyl; or a physiologicallyacceptable 3-ester, 20-ester, 21-ester, 3,20-diester, or 3,21-diesterthereof.
 2. A compound of claim 1, wherein R₃ is an acetyl thiosulfatesalt.
 3. A compound of claim 2 which is sodiumS-(3α-hydroxy-5α-pregnan-20-on-21-yl)thiosulfate; sodiumS-(3α-hydroxy-3β-methoxymethyl-5α-pregnan-20-on-21-yl)thiosulfate;sodium S-(3α-hydroxy-5β-pregnan-20-on-21-yl)thiosulfate; sodiumS-[3α-hydroxy-3β-(4'-hydroxybutynyl)-5β-pregnan-20-on-21-yl]thiosulfate; or sodiumS-(3α-hydroxy-3β-trifluoromethyl-5β-19-norpregnan-20-on-21-yl)thiosulfate.
 4. A compound of claim 2 which is sodiumS-(3α-hydroxy-3β-methyl-5α-pregnan-20-on-21-yl)thiosulfate.
 5. Acompound of the formula: ##STR3## or a physiologically acceptable3-ester, 20-ester, 21-ester, 3,20-diester, or 3,21-diester thereof;wherein:R is hydrogen, halogen, lower alkoxy, dialkylamino, alkyl orsubstituted alkyl; R₁ is a substituted aralkynyl, arylalkyl,arylalkenyl, optionally substituted aralkylalkynyl, alkanoyloxyalkynyl,optionally substituted heteroaryloxyalkynyl, oxoalkynyl or a ketalthereof, cyanoalkynyl, substituted heteroarylalkynyl, hydroxyalkynyl,alkoxyalkynyl, aminoalkynyl, acylaminoalkynyl, mercaptoalkynyl,hydroxyalkynyl dioic acid hemi-ester or a salt thereof, oralkynyloxyalkynyl; R₂ is hydrogen, hydroxy, alkoxy, alkanoyloxy,carbalkoxy, a keto group or amino group; R₃ is an acetyl group, a ketalof an acetyl group; an alkoxyacetyl group, an alkylthioacetyl group, analkylsulfinylacetyl group, an alkylsulfonylacetyl group, an aminoacetylgroup, a trifluoroacetyl group; a hydroxyacetyl group; analkoxyalkylacetyl group; a hydroxyalkyl group; a hydroxyacetyl dioicacid hemi-ester salt; an alkanoyloxyacetyl group; a sulfoxyacetyl group;an alkylacetyl group; a haloacetyl group; an ethynyl group; or a cyanogroup; or R₃ together with R₇ is a methylene group; or R₃ together withR₇ is an alkylmethylene group; or R₃ together with R₇ is analkoxymethylene group; R₄ is hydrogen or methyl, R₅ is hydrogen; R₆ ishydrogen, alkanoyl, aminocarbonyl or alkoxycarbonyl; R₇ is hydrogen,halogen, hydroxy, alkoxy, alkanoyloxy, or carbalkoxyl, or R₇ togetherwith R₃ is a methylene group, or R₇ together with R₃ is analkoxymethylene group; R₈ is hydrogen or halogen; R₉ is hydrogen,halogen, alkyl, alkoxy, arylalkoxy or amino; and R₁₀ is hydrogen,halogen, alkyl, haloalkyl, hydroxy, alkoxy, alkanoyloxy, carbalkoxyl,cyano, thiocyano or mercapto.
 6. The compound of claim 5, wherein thesubstituted aralkynyl and substituted heteroarylalkynyl groups of R₁ aresubstituted by one to five substituents selected from the groupconsisting of alkanoyl, carboxy, aryl, nitro, alkoxy, haloalkyl, halo,cyano, lower alkyl, halo, and --CONRR" groups, wherein R and R" areindependently lower alkyl groups;the heteroaryl of theheteroaryl-containing groups is selected from the group consisting ofpyridine, oxazole, indole, purine, pyrimidine, imidazole, benzimidazole,indazole, 2H-1,2,4-triazole, 1,2,3-triazole, 2H-1,2,3,4-tetrazole,1H-1,2,3,4-tetrazole, benzotriazole, 1,2,3-triazolo[4,5-b]pyridine,thiazole, isoxazole, pyrazole, quinoline, cytosine, thymine, uracil,adenine, guanine, pyrazine, picolinic acid, picoline, furoic acid,furfural, furyl alcohol, carbazole, 9H-pyrido[3,4-b]indole,isoquinoline, pyrrole, thiophene, furan, 9(10H)-acridone, phenoxazineand phenothiazine, and the aryl group of the aryl-containing groups isphenyl or naphthyl.
 7. A compound of claim 6, wherein R₁ isphenylethynyl, substituted by one to five substituents selected from thegroup consisting of alkanoyl, carboxy or alkyl ester thereof, aryl,nitro, alkoxy, haloalkyl, halo, cyano, lower alkyl, and --CONR'R"groups, wherein R' and R" are independently lower alkyl groups.
 8. Acompound of claim 7, wherein said phenylethynyl is substituted by onesubstituent at the 4'-position.
 9. A compound of claim 7, wherein saidphenylethynyl is substituted by one substituent at the 3'-position or5'-position.
 10. A compound of claim 7, which is selected from the groupconsistingof:3β-(4'-acetylphenylethynyl)-3β,21-dihydroxy-5α-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-19-nor-5β-pregnan-20-one,3β-(4'-carboxyphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one ethyl ester,3β-(4'-carboxyphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one ethyl ester,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-carboxyphenyl)ethynyl-3α-hydroxy-19-nor-5β-pregnan-20-one ethylester, 3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one,3β-(4'-biphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3α-hydroxy-3β-(4'-nitrophenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(4'-methoxyphenyl)ethynyl-5β-pregnan-20-one,3β-(4'-trifluoromethylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-chlorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(3'-acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-cyanophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(pentafluorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-[4'-(N,N-diethylcarboxamidophenyl)ethynyl]-3α-hydroxy-5β-pregnan-20-one,and 3α-hydroxy-3β-(4'-methylphenyl)ethynyl-5β-pregnan-20-one.
 11. Thecompound of claim 5, wherein:R is hydrogen, fluoro, chloro or loweralkoxy; R₁ is substituted arylethynyl; R₂ is hydrogen, a keto group or adimethylamino group; R₃ is a β-acetyl group, a dimethyl ketal of aβ-acetyl group, a trifluoroacetyl group, a β-(hydroxyacetyl) group, aβ-methoxymethylacetyl group, a β-(ethoxy)methyl-2'-methylene acetylgroup, a β-(1'-hydroxyethyl) group, a β-(1'-hydroxypropyl) group, aβ-(2'-hydroxy-2'propyl) group, a β-succinyloxyacetyl group, aβ-hydroxyacetyl sodium succinate group, a β-acetoxyacetyl group, aβ-sulfoxyacetyl group, a β-methylacetyl group, a β-haloacetyl group, ora β-ethynyl group; R₄ is hydrogen or methyl; R₅, R₆, R₈, R₉ and R₁₀ arehydrogen; the dotted lines all represent single bonds; and R₇ ishydrogen or, when R₃ is β-hydroxyacetyl, R₇ is hydrogen or hydroxy. 12.The compound of claim 5, wherein R₁ is substituted arylethynyl.
 13. Acompound of claim 12 which is3α-hydroxy-3β-(4'-nitrophenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(4'-methoxyphenyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-[2-(3',4'-dimethoxyphenyl)ethynyl]-5β-pregnan-20-one,3α-hydroxy-3β-(4'-methylphenyl)ethynyl-5β-pregnan-20-one,3β-(4'-trifluoromethylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3α-hydroxy-3β-(2'-methoxyphenyl)ethynyl-5β-pregnan-20-one,3β-(4'-dimethylaminophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-chlorophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one,3β-(4'-acetylphenyl)ethynyl-3α-hydroxy-5α-pregnan-20-one,3β-(4'-carboxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one ethyl ester;3α-hydroxy-3β-(4'-acetoxyacetylphenyl)ethynyl-5β-pregnan-20-one, or3β-(4'-cyanophenyl)ethynyl-3α-hydroxy-5β-pregnan-20-one.
 14. A compoundof claim 12 which is3β-(4'-acetylphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one;3β-(4'-carboxyphenylethynyl)-3α-hydroxy-19-nor-5β-pregnan-20-one ethylester; 3β-(4'-carboxyphenylethynyl)-3α-hydroxy-5α-pregnan-20-one ethylester;3β-[4'-(N,N-diethylcarboxamido)phenyl]ethynyl-3α-hydroxy-5.beta.-pregnan-20-one;3β-(4'-acetoxyphenylethynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one;3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one;3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5α-pregnan-20-one21-hemsuccinate salt; or3β-(4'-acetylphenylethynyl)-3α,21-dihydroxy-5β-pregnan-20-one21-hemsuccinate salt.
 15. A compound of claim 5, wherein R₁ is aralkyl.16. A compound of claim 15 which is3α-hydroxy-3β-benzyl-5β-pregnan-20-one;3α-hydroxy-3β-(2'-phenylethyl)-5β-pregnan-20-one;3α-hydroxy-3β-(3'-phenylpropyl)-5β-pregnan-20-one or3α-hydroxy-3β-[2-(3',4'-dimethoxyphenyl)ethyl]-5β-pregnan-20-one.
 17. Acompound of claim 5 wherein R₁ is cyanoalkynyl.
 18. A compound of claim17, which is 3α-hydroxy-3β-(5'-cyano-1'-pentynyl)-5β-pregnan-20-one or3α-hydroxy-3β-(4'-cyano-1'-butynyl)-5β-pregnan-20-one.
 19. A compound ofclaim 5, wherein R₁ is oxoalkynyl.
 20. A compound of claim 19 which is3α-hydroxy-3β-[6'-oxo-1'-heptynyl]-5β-pregnan-20-one;3α-hydroxy-3β-(7'-oxo-1'-octynyl)-5β-pregnan-20-one;3α-hydroxy-3β-(5'-oxo-1'-hexynyl)-5β-pregnan-20-one, or3α-hydroxy-3β-(5'-oxo-1'-pentynyl)-5β-pregnan-20-one.
 21. A compound ofclaim 5, wherein R₁ is hydroxyalkynyl or a physiologically acceptableester thereof.
 22. A compound of claim 21 which is3β-(4'(R/S)-hydroxypentynyl)-3α-hydroxy-5β-pregnan-20-one,3β-[5'-(R/S)-hydroxyhexynyl]-3α-hydroxy-5β-pregnan-20-one,3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(5'-hydroxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one hemisuccinatesodium salt, 3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(6'-hydroxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one 6'-hemisuccinatesodium salt, 3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one,3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one 4'-hemisuccinatesodium salt, 3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5α-pregnan-20-one,3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5α-pregnan-20-one 4'-hemisuccinatesodium salt,3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-19-norpregnan-20-one,3β-(4'-hydroxy-1'-butynyl)-3α-hydroxy-5β-19-norpregnan-20-one4'-hemisuccinate sodium salt,3β-[3'(R/S)-hydroxy-1'-butynyl]-3α-hydroxy-5α-pregnan-20-one or3β-(3'-hydroxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one.
 23. A compoundof claim 5 wherein R₁ is alkanoyloxyalkynyl.
 24. The compound of claim23 which is 3β-(3'-acetoxy-1'-propynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-acetoxy-1'-butynyl)-3α-hydroxy-5β-pregnan-20-one;3β-(4'-acetoxy-1'-butynyl)-3α-hydroxy-5α-pregnan-20-one;3β-(5'-acetoxy-1'-pentynyl)-3α-hydroxy-5β-pregnan-20-one; or3β-(6'-acetoxy-1'-hexynyl)-3α-hydroxy-5β-pregnan-20-one.
 25. A compoundof claim 1, wherein R₁ is alkynyloxyalkynyl.
 26. A compound of claim 25which is3α-hydroxy-3β-[3-(2'-propynyloxy)-1-propynyl]-5β-pregnan-20-one.
 27. Acompound of claim 5, wherein R₁ is alkoxyalkynyl.
 28. A compound ofclaim 27 which is 3α-hydroxy-3β-(3-methoxy-1-propynyl)-5β-pregnan-20-oneor 3α-hydroxy-3β-(3-methoxy-1-propynyl)-5α-pregnan-20-one.
 29. Acompound of claim 5, wherein R₁ is heteroaryloxyalkynyl.
 30. A compoundof claim 29 which is3α-hydroxy-3β-[3-(4'-pyridinyloxy)-1-propynyl]-5β-pregnan-20-one.
 31. Acompound of claim 5, wherein R₁ is substituted heteroarylalkynyl.
 32. Acompound of claim 31 which is3α-hydroxy-3β-(2'-thienyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(2-pyridyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-[3-(1'H-1,2,3-triazol-1'-yl)-1-propynyl]-5β-pregnan-20-one;3α-hydroxy-3β-[3-(2'H-1,2,3-triazol-2'-yl)-1-propynyl]-5β-pregnan-20-one,3α-hydroxy-3β-[3-(1'H-pyrazol-1'-yl)-1-propynyl]-5β-pregnan-20-one,3α-hydroxy-3β-(5'-acetyl-2'-thienyl)ethynyl-5β-pregnan-20-one,3α-hydroxy-3β-(3-pyridyl)ethynyl-5β-pregnan-20-one, or3α-hydroxy-3β-(4-pyridyl)ethynyl-5β-pregnan-20-one.
 33. A pharmaceuticalcomposition comprising the compound of claim 5 and a pharmaceuticallyacceptable carrier.
 34. A method of modulating the GABA_(A)receptor-chloride ionophore complex in an animal subject in need of suchtreatment through binding to the neurosteroid site on said complex,comprising administrating to said animal subject an amount, effective tomodulate said complex, of a compound of claim
 5. 35. A method oftreating stress or anxiety, treating mood disorders, alleviating seizureactivity, insomnia, premenstrual syndrome or postnatal depression, orinducing anesthesia, comprising administering to an animal subject inneed of such treatment an effective amount of the compound of claim 5.